Automotive Fuel Lines Including A Polyarylene Sulfide

ABSTRACT

A fuel line comprising a thermoplastic composition is described. The thermoplastic compositions exhibit high strength and flexibility and can be used to form one or more layers of single layer or multi-layer fuel lines. Methods for forming the thermoplastic compositions are also described. Formation methods include dynamic vulcanization of a composition that includes an impact modifier dispersed throughout a polyarylene sulfide. A crosslinking agent is combined with the other components of the composition following dispersal of the impact modifier. The crosslinking agent reacts with the impact modifier to form crosslinks within and among the polymer chains of the impact modifier. The compositions can exhibit excellent physical characteristics at extreme temperatures.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims filing benefit of U.S. Provisional PatentApplication Ser. No. 61/623,618 having a filing date of Apr. 13, 2012;U.S. Provisional Patent Application Ser. No. 61/665,423 having a filingdate of Jun. 28, 2012; U.S. Provisional Patent Application Ser. No.61/678,370 having a filing date of Aug. 1, 2012; U.S. Provisional PatentApplication Ser. No. 61/703,331 having a filing date of Sep. 20, 2012;U.S. Provisional Patent Application Ser. No. 61/707,380 having a filingdate of Sep. 28, 2012, and U.S. Provisional Patent Application Ser. No.61/717,955 having a filing date of Oct. 24, 2012, all of which areincorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

Automotive fuel line tubing and hoses include both monolayer andmultilayer materials. Traditionally, metals were used to form fuellines, but automotive manufacturers have been replacing metals whereverpossible to reduce weight and CO₂ emissions. More recently, fuel linetubing and hoses have been formed of aliphatic polyamide (PA), high-heatrubber composites, and braided polytetrafluoroethylene (PTFE).Unfortunately, these materials have often provided less than idealperformance and/or required complex and costly formation techniques. Forexample, while braided PTFE and high heat rubber composites can be usedin high heat environments, the constructions are often complex andcostly. The use of aliphatic polyamide also has limitations. Forinstance, PA12 has limitations with regard to both permeation of fueland long term heat aging at the higher temperatures present in newervehicles. Thus, fuel lines formed of these materials often require aheat shield at added weight and cost. In addition, multi-layerconstructions of these materials are often subject to delamination,especially where fluoropolymer layers are present, and generally requirespecial chemical bonding between layers.

There are multiple different requirements for the lines in the fuelsystem, some of them varying depending upon the final application. Forexample, in the vapor line, a good barrier property must be provided toprevent vapors from escaping into the environment. In addition, thereare thermal and mechanical requirements that should be maintained over along lifetime. Included in the mechanical requirements are sufficientflexibility and impact strength for both fabrication and safety. Inaddition to the requirements for vapor lines, liquid lines also meet therequirement that essentially no materials used in forming the fuel linecontaminate the fuel, which could lead to problems such as clogged fuelinjectors. Thus, the lines must be chemically resistant to the liquidsto be carried by the lines. Many polymers that have been examined foruse in forming fuel lines to date have leached oligomers that can clogthe fuel system and reduce engine performance.

Polyarylene sulfides are high-performance polymers that may withstandhigh thermal, chemical, and mechanical stresses and are beneficiallyutilized in a wide variety of applications. Polyarylene sulfides haveoften been blended with other polymers to improve characteristics of theproduct composition. For example, elastomeric impact modifiers have beenfound beneficial for improvement of the physical properties ofthermoplastic compositions. Compositions including blends of polyarylenesulfides with impact modifying polymers have been considered for highperformance, high temperature applications.

Unfortunately, elastomeric polymers generally considered useful forimpact modification are not compatible with polyarylene sulfides andphase separation has been a problem in forming compositions of the two.Attempts have been made to improve the composition formation, forinstance through the utilization of compatibilizers. However, even uponsuch modifications, compositions including polyarylene sulfides incombination with impact modifying polymers still fail to provide productperformance as desired, particularly in applications that require bothhigh heat resistance and high impact resistance.

What are needed in the art are thermoplastic compositions that can beused to form automotive fuel lines that exhibit excellent barrierproperties as well as good mechanical characteristics, including bothgood impact resistance and good flexibility, so as to form fuel linesthat can be quickly and easily installed and that can exhibit desirablecharacteristics over a long working life.

SUMMARY OF THE INVENTION

Disclosed in one embodiment is a fuel line that includes a thermoplasticcomposition. The thermoplastic composition includes a polyarylenesulfide and a crosslinked impact modifier. A fuel line as describedherein is a tubular member including a hollow passage therethrough forpassage of a fluid.

Also disclosed is a method for forming a fuel line. The method caninclude molding the thermoplastic composition including a polyarylenesulfide and a crosslinked impact modifier according to any of a varietyof techniques to form a fuel line.

Fuel lines as may be formed from the thermoplastic composition can beeither single layer tubes or multi-layer hoses. In addition, fuel linesencompassed herein can include fuel lines for use in carrying liquidfuel, vaporous fuel, or a combination thereof.

BRIEF DESCRIPTION OF THE FIGURES

The present disclosure may be better understood with reference to thefollowing figures:

FIG. 1 illustrates a portion of a fuel system that can incorporate oneor more fuel lines as described herein.

FIG. 2 is a single layer tube as may be formed from the thermoplasticcomposition.

FIG. 3 is a two layer hose, one or more layers of which may be formedfrom the thermoplastic composition.

FIG. 4 is a three layer hose, one or more layers of which may be formedfrom the thermoplastic composition.

FIG. 5 is a schematic representation of a process for forming thethermoplastic composition.

FIG. 6 illustrates a continuous blow molding process as may be utilizedin forming a fuel line from the thermoplastic composition.

FIG. 7 illustrates the sample used in determination of melt strength andmelt elongation of thermoplastic compositions described herein.

FIG. 8 illustrates the effect of temperature change on the notchedCharpy impact strength of a thermoplastic composition as describedherein and that of a comparison composition.

FIG. 9 is a scanning electron microscope image of a thermoplasticcomposition as described herein (FIG. 9B) and a comparison thermoplasticcomposition (FIG. 9A).

FIG. 10 compares the effect of sulfuric acid exposure on strengthcharacteristics of thermoplastic compositions as described herein and acomparison composition.

FIG. 11 provides the log of the complex viscosity obtained forthermoplastic compositions described herein as a function of the shearrate.

FIG. 12 provides the melt strength of thermoplastic compositionsdescribed herein as a function of the Hencky strain.

FIG. 13 provides the melt elongation for thermoplastic compositionsdescribed herein as a function of Hencky strain.

FIG. 14 illustrates a blow molded container formed of the thermoplasticcomposition.

FIG. 15A and FIG. 15B are cross sectional images of the container shownin FIG. 14.

FIG. 16 illustrates the daily weight loss for testing samples indetermination of permeation resistance of thermoplastic compositions toCE10.

FIG. 17 illustrates the daily weight loss for testing samples indetermination of permeation resistance of thermoplastic compositions toCM15A.

FIG. 18 illustrates the daily weight loss for testing samples indetermination of permeation resistance of thermoplastic compositions tomethanol.

DETAILED DESCRIPTION

It is to be understood by one of ordinary skill in the art that thepresent discussion is a description of exemplary embodiments only, andis not intended as limiting the broader aspects of the presentdisclosure.

The present disclosure is generally directed to fuel lines that includea thermoplastic composition that exhibits excellent strength andflexibility characteristics as well as resistance to chemicaldegradation due to contact with materials that may be carried within thefuel lines as well as materials that may contact the external surface ofthe fuel lines such as water, oils, gasoline, gases, synthetic ornatural chemicals, etc. Beneficially, the thermoplastic composition canmaintain good physical characteristics even when utilized in extremetemperature applications and can also maintain good physicalcharacteristics under the motive forces that will be encountered overthe lifetime of the fuel line.

The thermoplastic composition can be formed according to a meltprocessing technique that includes combining a polyarylene sulfide withan impact modifier to form a mixture and subjecting the mixture todynamic vulcanization. More specifically, the polyarylene sulfide can becombined with the impact modifier and this mixture can be subjected toshear conditions such that the impact modifier becomes well distributedthroughout the polyarylene sulfide. Following formation of the mixture,a polyfunctional crosslinking agent can be added. The polyfunctionalcrosslinking agent can react with the components of the mixture to formcrosslinks in the composition, for instance within and between thepolymer chains of the impact modifier.

Without being bound to any particular theory, it is believed that byadding the polyfunctional crosslinking agent following distribution ofthe impact modifier throughout the polyarylene sulfide, interactionbetween the polyarylene sulfide, the impact modifier, and thecrosslinking agent within the melt processing unit can be improved,leading to improved distribution of the crosslinked impact modifierthroughout the composition. The improved distribution of the crosslinkedimpact modifier throughout the composition can improve the strength andflexibility characteristics of the composition, e.g., the ability of thecomposition to maintain strength under deformation, as well as provide acomposition with good processibility that can be utilized to form a fuelline that can exhibit excellent resistance to degradation under avariety of conditions.

The high strength and flexibility characteristics of the thermoplasticcomposition can be evident by examination of the tensile, flexural,and/or impact properties of the materials. For example, thethermoplastic composition can have a notched Charpy impact strength ofgreater than about 3 kJ/m², greater than about 3.5 kJ/m², greater thanabout 5 kJ/m², greater than about 10 kJ/m², greater than about 15 kJ/m²,greater than about 30 kJ/m², greater than about 33 kJ/m², greater thanabout 40 kJ/m², greater than about 45 kJ/m², or greater than about 50kJ/m² as determined according to ISO Test No. 179-1 (technicallyequivalent to ASTM D256, Method B) at 23° C. The unnotched Charpysamples do not break under testing conditions of ISO Test No. 180 at 23°C. (technically equivalent to ASTM D256).

Beneficially, the thermoplastic composition can maintain good physicalcharacteristics even at extreme temperatures, including both high andlow temperatures. For instance, the thermoplastic composition can have anotched Charpy impact strength of greater than about 8 kJ/m², greaterthan about 9 kJ/m², greater than about 10 kJ/m², greater than about 14kJ/m², greater than about 15 kJ/m², greater than about 18 kJ/m² , orgreater than about 20 kJ/m² as determined according to ISO Test No.179-1 at −30° C.; and can have a notched Charpy impact strength ofgreater than about 8 kJ/m², greater than about 9 kJ/m², greater thanabout 10 kJ/m², greater than about 11 kJ/m², greater than about 12kJ/m², or greater than about 15 kJ/m² as determined according to ISOTest No. 179-1 at −40° C.

Moreover, the effect of temperature change on the thermoplasticcomposition can be surprisingly small. For instance, the ratio of thenotched Charpy impact strength as determined according to ISO Test No.179-1 at 23° C. to that at −30° C. can be greater than about 3.5,greater than about 3.6, or greater than about 3.7. Thus, and asdescribed in more detail in the example section below, as thetemperature increases the impact strength of the thermoplasticcomposition also increases, as expected, but the rate of increase of theimpact strength is very high, particularly as compared to a compositionthat does not include the dynamically crosslinked impact modifier.Accordingly, the thermoplastic composition can exhibit excellentstrength characteristics at a wide range of temperatures.

The thermoplastic composition can exhibit very good tensilecharacteristics. For example, the thermoplastic composition can have atensile elongation at yield of greater than about 4.5%, greater thanabout 6%, greater than about 7%, greater than about 10%, greater thanabout 25%, greater than about 35%, greater than about 50%, greater thanabout 70%, greater than about 75%, greater than about 80%, or greaterthan about 90%. Similarly, the tensile elongation at break can be quitehigh, for instance greater than about 10%, greater than about 25%,greater than about 35%, greater than about 50%, greater than about 70%,greater than about 75%, greater than about 80%, or greater than about90%. The strain at break can be greater than about 5%, greater thanabout 15%, greater than about 20%, or greater than about 25%. Forinstance the strain at break can be about 90%. The yield strain canlikewise be high, for instance greater than about 5%, greater than about15%, greater than about 20%, or greater than about 25%. The yield stresscan be, for example, greater than about 50% or greater than about 53%.The thermoplastic composition may have a tensile strength at break ofgreater than about 30 MPa, greater than about 35 MPa, greater than about40 MPa, greater than about 45 MPa, or greater than about 70 MPa.

In addition, the thermoplastic composition can have a relatively lowtensile modulus. For instance, the thermoplastic composition can have atensile modulus less than about 3000 MPa, less than about 2300 MPa, lessthan about 2000 MPa, less than about 1500 MPa, or less than about 1100MPa as determined according to ISO Test No. 527 at a temperature of 23°C. and a test speed of 5 mm/min.

The thermoplastic composition can exhibit good characteristics afterannealing as well. For instance, following annealing at a temperature ofabout 230° C. for a period of time of about 2 hours, the tensile modulusof the composition can be less than about 2500 MPa, less than about 2300MPa, or less than about 2250 MPa. The tensile strength at break afterannealing can be greater than about 50 MPa, or greater than about 55MPa, as measured according to ISO Test No. 527 at a temperature of 23°C. and a test speed of 5 mm/min.

The thermoplastic composition can also be utilized continuously at hightemperature, for instance at a continuous use temperature of up to about150° C., about 160° C., or about 165° C. without loss of tensilestrength. For example, the thermoplastic composition can maintaingreater than about 95%, for instance about 100% of the original tensilestrength after 1000 hours of heat aging at 165° C. and can maintaingreater than about 95%, for instance about 100% of the original tensileelongation at yield after 1000 hours heat aging at 135° C.

Tensile characteristics can be determined according to ISO Test No. 527at a temperature of 23° C. and a test speed of 5 mm/min or 50 mm/min(technically equivalent to ASTM D623 at 23° C.).

The flexural characteristics of the composition can be determinedaccording to ISO Test No. 178 (technically equivalent to ASTM D790 at atemperature of 23° C. and a testing speed of 2 mm/min. For example, theflexural modulus of the composition can be less than about 2500 MPa,less than about 2300 MPa, less than about 2000 MPa, less than about 1800MPa, or less than about 1500 MPa. The thermoplastic composition may havea flexural strength at break of greater than about 30 MPa, greater thanabout 35 MPa, greater than about 40 MPa, greater than about 45 MPa, orgreater than about 70 MPa.

The deflection temperature under load of the thermoplastic compositioncan be relatively high. For example, the deflection temperature underload of the thermoplastic composition can be greater than about 80° C.,greater than about 90° C., greater than about 100° C., or greater thanabout 105° C., as determined according to ISO Test No. 75-2 (technicallyequivalent to ASTM D790) at 1.8 MPa.

The Vicat softening point can be greater than about 200° C. or greaterthan about 250° C., for instance about 270° C. as determined accordingto the Vicat A test when a load of 10 N is used at a heating rate of 50K/hr. For the Vicat B test, when a load of 50 N is used at a heatingrate of 50 K/hr, the Vicat softening point can be greater than about100° C., greater than about 150° C. greater than about 175° C., orgreater than about 190° C., for instance about 200° C. The Vicatsoftening point can be determined according to ISO Test No. 306(technically equivalent to ASTM D1525).

The thermoplastic composition can also exhibit excellent stabilityduring long term exposure to harsh environmental conditions. Forinstance, under long term exposure to an acidic environment, thethermoplastic composition can exhibit little loss in strengthcharacteristics. For instance, following 500 hours exposure to a strongacid (e.g., a solution of about 5% or more strong acid such as sulfuricacid, hydrochloric acid, nitric acid, perchloric acid, etc.), thethermoplastic composition can exhibit a loss in Charpy notched impactstrength of less than about 17%, or less than about 16% followingexposure of about 500 hours to a strong acid solution at a temperatureof about 40° C., and can exhibit a loss in Charpy notched impactstrength of less than about 25%, or less than about 22% followingexposure of about 500 hours to a strong acid solution at a temperatureof about 80° C. Even under harsher conditions, for instance in a 10%sulfuric acid solution held at a temperature of about 80° C. for 1000hours, the thermoplastic composition can maintain about 80% or more ofthe initial Charpy notched impact strength. The thermoplasticcomposition can also maintain desirable strength characteristicsfollowing exposure to other potentially degrading materials, such assalts, e.g., road salts as may be encountered by fuel lines.

Permeation resistance can be important for fuel lines. The thermoplasticcomposition can exhibit excellent permeation resistance to a widevariety of fuels. For instance, a fuel line formed of the thermoplasticcomposition can exhibit a permeation resistance to a fuel (e.g.,gasoline, diesel fuel, jet fuel, blended fuels, etc.) of less than about3 g-mm/m²-day, less than about 2 g-mm/m²-day, less than about 1g-mm/m²-day, or less than about 0.5 g-mm/m²-day. By way of example, thethermoplastic composition (or a fuel line formed of the thermoplasticcomposition) can exhibit a permeation resistance to an ethanol blend ofethanol/iso-octane/toluene at a weight ratio of 10:45:45 at 40° C. ofless than about 3 g-mm/m²-day, less than about 2.5 g-mm/m²-day, lessthan about 1 g-mm/m²-day, or less than about 0.1 g-mm/m²-day. Thepermeation resistance to a blend of 15 wt. % methanol and 85 wt. %oxygenated fuel (CM15A) at 40° C. can be less than about 3 g-mm/m²-day,less than about 2.5 g-mm/m²-day, less than about 1 g-mm/m²-day, lessthan about 0.5 g-mm/m²-day, less than about 0.3 g-mm/m²-day, or lessthan about 0.15 g-mm/m²-day. The permeation resistance to methanol at40° C. can be less than about 1 g-mm/m²-day, less than about 0.5g-mm/m²-day, less than about 0.25 g-mm/m²-day, less than about 0.1g-mm/m²-day, or less than about 0.06 g-mm/m²-day. Permeation resistancecan be determined according to SAE Testing Method No. J2665. Inaddition, the thermoplastic composition can maintain the originaldensity following long term exposure to hydrocarbons. For example, thecomposition can maintain greater than about 95% of original density,greater than about 96% of original density, such as about 99% oforiginal density following long term (e.g., greater than about 14 days)exposure to hydrocarbons such as heptane, cyclohexane, toluene, and soforth, or combinations of hydrocarbons.

The thermoplastic composition can exhibit good heat resistance and flameretardant characteristics. For instance, the composition can meet theV-0 flammability standard at a thickness of 0.2 millimeters. The flameretarding efficacy may be determined according to the UL 94 VerticalBurn Test procedure of the “Test for Flammability of Plastic Materialsfor Parts in Devices and Appliances”, 5th Edition, Oct. 29, 1996. Theratings according to the UL 94 test are listed in the following table:

Rating Afterflame Time (s) Burning Drips Burn to Clamp V-0 <10 No No V-1<30 No No V-2 <30 Yes No Fail <30 Yes Fail >30 No

The “afterflame time” is an average value determined by dividing thetotal afterflame time (an aggregate value of all samples tested) by thenumber of samples. The total afterflame time is the sum of the time (inseconds) that all the samples remained ignited after two separateapplications of a flame as described in the UL-94 VTM test. Shorter timeperiods indicate better flame resistance, i.e., the flame went outfaster. For a V-0 rating, the total afterflame time for five (5)samples, each having two applications of flame, must not exceed 50seconds. Using the flame retardant of the present invention, articlesmay achieve at least a V-1 rating, and typically a V-0 rating, forspecimens having a thickness of 0.2 millimeters.

The thermoplastic composition can also exhibit good processingcharacteristics, for instance as demonstrated by the melt viscosity ofthe composition. For instance, the thermoplastic composition can have amelt viscosity of less than about 2800 poise as measured on a capillaryrheometer at 316° C. and 400 sec⁻¹ with the viscosity measurement takenafter five minutes of constant shear. Moreover, the thermoplasticcomposition can exhibit improved melt stability over time as compared tothermoplastic compositions that include polyarylene sulfide and do notinclude crosslinked impact modifiers. While thermoplastic compositionsthat include polyarylene sulfide and do not include a crosslinked impactmodifier tend to exhibit an increase in melt viscosity over time,disclosed compositions can maintain or even decrease in melt viscosityover time.

The thermoplastic composition can have a complex viscosity as determinedat low shear (0.1 radians per second (rad/s)) and 310° C. of greaterthan about 10 kPa/sec, greater than about 25 kPa/sec, greater than about40 kPa/sec, greater than about 50 kPa/sec, greater than about 75kPa/sec, greater than about 200 kPa/sec, greater than about 250 kPa/sec,greater than about 300 kPa/sec, greater than about 350 kPa/sec, greaterthan about 400 kPa/sec, or greater than about 450 kPa/sec. Higher valuefor complex viscosity at low shear is indicative of the crosslinkedstructure of the composition and the higher melt strength of thethermoplastic composition. In addition, the thermoplastic compositioncan exhibit high shear sensitivity, which indicates excellentcharacteristics for use in formation processes such as blow molding andextrusion processing.

The thermoplastic composition can be processed according to standardformation techniques to form a fuel line that can be either a singlelayer fuel tube or a multi-layer fuel hose. Fuel lines as encompassedherein are tubular shaped members having a hollow passage therethroughthat allows passage of a fluid, a liquid, a gas, or a mixture thereof,through the fuel line. A fuel line can include the thermoplasticcomposition throughout the entire fuel line or only a portion of thefuel line. For instance, when considering a fuel line having a largeaspect ratio (L/D>1), the fuel line can be formed such that thethermoplastic composition extends along a section of the fuel line andan adjacent section can be formed of a different composition, forinstance a different thermoplastic composition. Such a fuel line can beformed by, e.g., altering the material that is fed to a molding deviceduring a formation process. The fuel line can include an area in whichthe two materials are mixed that represents a border region between afirst section and a second section formed of different materials. A fuelline can include a single section formed of the thermoplasticcomposition or a plurality of sections, as desired. Moreover, othersections of a fuel line can be formed of multiple different materials.By way of example, both ends of the fuel line can be formed of thethermoplastic composition and a center section can be formed of a lessflexible composition. Thus, the more flexible ends can be utilized totightly affix the fuel line to other components of a system.Alternatively, a center section of a fuel line could be formed from thethermoplastic composition, which can improve flexibility of the fuelline in that section, making installation of the fuel line easier.

FIG. 1 illustrates a portion of the fuel system that can include a fuelline that includes the thermoplastic composition. FIG. 1 illustrates theintake portion generally 1 of a fuel system and includes a fuel fillerneck 2, a filler tube 24, a fuel tank 28, a vent tube 26, and a gas cap14, and is supported by an automobile body 16, which includes a movablecover 20 to conceal the gas cap 14. The filler neck 2 generally includesa funnel-shaped member 8. The filler neck 2 may receive a nozzlereceptor 12, which is an insert adapted to receive a fuel nozzle 6during fueling. The member 8 is defined at one end by an inlet opening10 adapted to receive the gas cap 14, which screws directly into threads36 integrally formed in the member 8.

An opposite end of the member 8 is defined by an outlet opening 22,which is coupled to a first end 34 of a fuel line 24. The fuel line 24can be a single layer tube or a multi-layer hose formed of thethermoplastic composition. At a second end 32, the fuel line 24 iscoupled to the fuel tank 28. The fuel tank system 4 may also include avent line 26 that connects to the member 8 at funnel vent opening 30 andto the fuel tank 28 at fuel tank opening 40. The vent line 26 allowsdisplaced vapors in the fuel tank 28 to be vented during fueling. Thevent line 26 may also be a single layer tube or a multi-layer hose thatcan be formed from the thermoplastic composition.

Any fuel line that has a generally tubular shape and includes a hollowpassage through the line (i.e., in the axial direction of the tubularmember) as may be included in a vehicle engine, including both gasolineand diesel engines, may include one or more layers formed of thethermoplastic composition, and it should be understood that the fuellines are not in any way limited to the in-take portion of the fuelsystem as illustrated in FIG. 1. For example, fuel lines encompassedherein include fuel feed lines that carry fuel from the fuel tank to theengine and can be located downstream and/or upstream of the fuel filter.Other fuel lines as may incorporate the thermoplastic composition caninclude, without limitation, fuel return lines, fuel bypass lines, fuelcrossover lines, breather lines, evaporation lines, etc.

FIG. 2 illustrates a perspective view of a single layer tube 50 formedof the thermoplastic composition. A single layer tube can be utilized,for example, in forming a vent line 26 and/or a fuel line 24 asillustrated in FIG. 1. A single layer tube 50 can generally have a wallthickness of less than about 3 millimeters, for instance from about 0.5to about 2.5 millimeters, or from about 0.8 to about 2 millimeters.Single layer tube 50 can generally have a cross sectional diameter ofless than about 10 millimeters, or less than about 5 millimeters in oneembodiment. The length of a single layer tube can vary depending on thespecific application and can be relatively long, for instance about 1meter long or more, or can be short, for instance less than about 50centimeters, or less than about 10 centimeters. Additionally, a singlelayer tube 50 can have a corrugated surface or a smooth surface.

A fuel line that incorporates the thermoplastic composition can be amulti-layered tubular member. FIG. 3 illustrates a two-layered fuel line60 and FIG. 4 illustrates a three-layered fuel line 70 as mayincorporate the thermoplastic composition in one or more layers of thefuel line 60, 70. Multi-layer fuel lines are not limited to two or threelayers, however, and additional layers may be included in a fuel line,as desired. Multi-layer fuel lines, similar to single layer fuel tubes,can be formed to have a wide variety of cross sectional and lengthdimensions, as is known in the art. In general, each layer of amulti-layer fuel line can have a wall thickness of less than about 2millimeters, or less than about 1 millimeter; and the inner diameter ofthe multi-layer fuel line can generally be less than about 100millimeters, less than about 50 millimeters, or less than about 30millimeters.

As can be seen, two-layered fuel line 60 includes an inner layer 61 andan outer layer 62. Three-layered fuel line 70 includes an inner layer71, an intermediate layer 72, and an outer layer 73. The excellentbarrier properties of the thermoplastic composition combined with thechemical resistance properties of the thermoplastic composition make itsuitable for use in forming an inner layer of a multi-layer fuel line.For example, the inner layers 61, 71 of the illustrated fuel lines 60,70 can be formed of the thermoplastic composition.

The thermoplastic composition is not limited to utilization as an innerlayer of a multi-layer fuel line. The high strength characteristics ofthe thermoplastic composition combined with the excellent barrierproperties and good flexibility make the thermoplastic compositionsuitable for use in forming outer layers and/or intermediate layers of amulti-layer fuel line in addition to or alternative to forming the innerlayer of the multi-layer fuel line.

In those embodiments in which the thermoplastic composition forms alayer of the multi-layer hose, additional layers can be formed of amaterial that is the same or different than the thermoplasticcomposition that forms the layer of the thermoplastic composition. Forexample, when considering a fuel line that includes three or morelayers, an intermediate layer 72 can be formed of a material thatexhibits high resistance to pressure and mechanical effects. By way ofexample, layer 72 can be formed of polyamides from the group ofhomopolyamides, co-polyamides, their blends or mixtures which each otheror with other polymers. Alternatively, layer 72 can be formed of a fiberreinforced material such as a fiber-reinforced resin composite or thelike. For example, a polyaramid (e.g., Kevlar®) woven mat can beutilized to form an intermediate layer 72 that is highly resistant tomechanical assaults. Such materials may also be utilized to form aninner layer of a fuel hose in those embodiments in which thethermoplastic composition is utilized for one or more layers other thanthe inner layer of the fuel hose. An intermediate layer may be formedover the pre-formed inner layer or may be formed first, and the innerlayer may be formed on the interior surface of the first-formed layer,for instance according to a blow molding method.

Outer layer 62, 73 of a multi-layer fuel hose 60, 70 can provideprotection from external assaults. For example, a multi-layer fuel hosecan include an outer layer 62, 73 formed from the thermoplasticcomposition or from an adequate kind of rubber material having highlevels of chipping, weather, flame and cold resistance. Examples of suchmaterials include thermoplastic elastomer such as polyamidethermoplastic elastomer, polyester thermoplastic elastomer, polyolefinthermoplastic elastomer, and styrene thermoplastic elastomer. Suitablematerials for outer layers 62, 73 include, without limitation,ethylene-propylene-diene terpolymer rubber, ethylene-propylene rubber,chlorosulfonated polyethylene rubber, a blend of acrylonitrile-butadienerubber and polyvinyl chloride, a blend of acrylonitrile-butadiene rubberand ethylene-propylene-diene terpolymer rubber, and chlorinatedpolyethylene rubber.

Outer layer 62, 73 can alternatively be formed of a harder, lessflexible material, such as a polyolefin, polyvinylchloride, or a highdensity polyethylene, a fiber reinforced composite material such as aglass fiber composite or a carbon fiber composite.

A multi-layer fuel line may further contain one or more adhesive layersformed from adhesive materials such as, for example, polyesterpolyurethanes, polyether polyurethanes, polyester elastomers, polyetherelastomers, polyamides, polyether polyamides, polyether polyimides,functionalized polyolefins, and the like.

FIG. 5 schematically illustrates a process that can be used in formingthe thermoplastic composition used in forming a fuel line. Asillustrated, the components of the thermoplastic composition may bemelt-kneaded in a melt processing unit such as an extruder 300. Extruder300 can be any extruder as is known in the art including, withoutlimitation, a single, twin, or multi-screw extruder, a co-rotating orcounter rotating extruder, an intermeshing or non-intermeshing extruder,and so forth. In one embodiment, the composition may be melt processedin an extruder 300 that includes multiple zones or barrels. In theillustrated embodiment, extruder 300 includes 10 barrels numbered321-330 along the length of the extruder 300, as shown. Each barrel321-330 can include one or more feed lines 314, 316, vents 312,temperature controls, etc. that can be independently operated. A generalpurpose screw design can be used to melt process the thermoplasticcomposition. By way of example, a thermoplastic composition may be meltmixed using a twin screw extruder such as a Coperion co-rotating fullyintermeshing twin screw extruder.

In forming a thermoplastic composition, a polyarylene sulfide can be fedto the extruder 300 at a main feed throat 314. For instance, thepolyarylene sulfide may be fed to the main feed throat 314 at the firstbarrel 321 by means of a metering feeder. The polyarylene sulfide can bemelted and mixed with the other components of the composition as itprogresses through the extruder 300. The impact modifier can be added tothe composition in conjunction with the thermoplastic composition at themain feed throat 314 or downstream of the main feed throat, as desired.

At a point downstream of the main feed throat 314, and followingaddition of the impact modifier to the composition, the crosslinkingagent can be added to the composition. For instance, in the illustratedembodiment, a second feed line 316 at barrel 326 can be utilized foraddition of the crosslinking agent. The point of addition for thecrosslinking agent is not particularly limited. However, thecrosslinking agent can be added to the composition at a point after thepolyarylene sulfide has been mixed with the impact modifier under shearsuch that the impact modifier is well distributed throughout thepolyarylene sulfide.

The polyarylene sulfide may be a polyarylene thioether containing repeatunits of the formula (I):

—[(Ar¹)_(n)—X]_(m)—[(Ar²)_(i)—Y]_(j)—[(Ar³)_(k)—Z]_(l)—[(Ar⁴)_(o)—W]_(p)—  (I)

wherein Ar¹, Ar², Ar³, and Ar⁴ are the same or different and are aryleneunits of 6 to 18 carbon atoms; W, X, Y, and Z are the same or differentand are bivalent linking groups selected from —SO₂—, —S—, —SO—, —CO—,—O—, —COO— or alkylene or alkylidene groups of 1 to 6 carbon atoms andwherein at least one of the linking groups is —S—; and n, m, i, j, k, l,o, and p are independently zero or 1, 2, 3, or 4, subject to the provisothat their sum total is not less than 2. The arylene units Ar¹, Ar²,Ar³, and Ar⁴ may be selectively substituted or unsubstituted.Advantageous arylene systems are phenylene, biphenylene, naphthylene,anthracene and phenanthrene. The polyarylene sulfide typically includesmore than about 30 mol %, more than about 50 mol %, or more than about70 mol % arylene sulfide (—S—) units. In one embodiment the polyarylenesulfide includes at least 85 mol % sulfide linkages attached directly totwo aromatic rings.

In one embodiment, the polyarylene sulfide is a polyphenylene sulfide,defined herein as containing the phenylene sulfide structure—(C₆H₄—S)_(n)— (wherein n is an integer of 1 or more) as a componentthereof.

The polyarylene sulfide may be synthesized prior to forming thethermoplastic composition, though this is not a requirement of aprocess. For example, a polyarylene sulfide can be purchased from knownsuppliers. For instance Fortron® polyphenylene sulfide available fromTicona of Florence, Kent., USA can be purchased and utilized as thepolyarylene sulfide. When the polyarylene sulfide is synthesized,synthesis techniques as are generally known in the art may be utilized.By way of example, a process for producing a polyarylene sulfide caninclude reacting a material that provides a hydrosulfide ion, e.g., analkali metal sulfide, with a dihaloaromatic compound in an organic amidesolvent.

The alkali metal sulfide can be, for example, lithium sulfide, sodiumsulfide, potassium sulfide, rubidium sulfide, cesium sulfide or amixture thereof. When the alkali metal sulfide is a hydrate or anaqueous mixture, the alkali metal sulfide can be processed according toa dehydrating operation in advance of the polymerization reaction. Analkali metal sulfide can also be generated in situ. In addition, a smallamount of an alkali metal hydroxide can be included in the reaction toremove or react impurities (e.g., to change such impurities to harmlessmaterials) such as an alkali metal polysulfide or an alkali metalthiosulfate, which may be present in a very small amount with the alkalimetal sulfide.

The dihaloaromatic compound can be, without limitation, ano-dihalobenzene, m-dihalobenzene, p-dihalobenzene, dihalotoluene,dihalonaphthalene, methoxy-dihalobenzene, dihalobiphenyl, dihalobenzoicacid, dihalodiphenyl ether, dihalodiphenyl sulfone, dihalodiphenylsulfoxide or dihalodiphenyl ketone. Dihaloaromatic compounds may be usedeither singly or in any combination thereof. Specific exemplarydihaloaromatic compounds can include, without limitation,p-dichlorobenzene; m-dichlorobenzene; o-dichlorobenzene;2,5-dichlorotoluene; 1,4-dibromobenzene; 1,4-dichloronaphthalene;1-methoxy-2,5-dichlorobenzene; 4,4′-dichlorobiphenyl;3,5-dichlorobenzoic acid; 4,4′-dichlorodiphenyl ether;4,4′-dichlorodiphenylsulfone; 4,4′-dichlorodiphenylsulfoxide; and4,4′-dichlorodiphenyl ketone.

The halogen atom can be fluorine, chlorine, bromine or iodine, and 2halogen atoms in the same dihalo-aromatic compound may be the same ordifferent from each other. In one embodiment, o-dichlorobenzene,m-dichlorobenzene, p-dichlorobenzene or a mixture of 2 or more compoundsthereof is used as the dihalo-aromatic compound.

As is known in the art, it is also possible to use a monohalo compound(not necessarily an aromatic compound) in combination with thedihaloaromatic compound in order to form end groups of the polyarylenesulfide or to regulate the polymerization reaction and/or the molecularweight of the polyarylene sulfide.

The polyarylene sulfide may be a homopolymer or may be a copolymer. By asuitable, selective combination of dihaloaromatic compounds, apolyarylene sulfide copolymer can be formed containing not less than twodifferent units. For instance, in the case where p-dichlorobenzene isused in combination with m-dichlorobenzene or4,4′-dichlorodiphenylsulfone, a polyarylene sulfide copolymer can beformed containing segments having the structure of formula (II):

and segments having the structure of formula (III):

or segments having the structure of formula (IV):

In general, the amount of the dihaloaromatic compound(s) per mole of theeffective amount of the charged alkali metal sulfide can generally befrom 1.0 to 2.0 moles, from 1.05 to 2.0 moles, or from 1.1 to 1.7 moles.Thus, the polyarylene sulfide can include alkyl halide (generally alkylchloride) end groups.

A process for producing the polyarylene sulfide can include carrying outthe polymerization reaction in an organic amide solvent. Exemplaryorganic amide solvents used in a polymerization reaction can include,without limitation, N-methyl-2-pyrrolidone; N-ethyl-2-pyrrolidone;N,N-dimethylformamide; N,N-dimethylacetamide; N-methylcaprolactam;tetramethylurea; dimethylimidazolidinone; hexamethyl phosphoric acidtriamide and mixtures thereof. The amount of the organic amide solventused in the reaction can be, e.g., from 0.2 to 5 kilograms per mole(kg/mol) of the effective amount of the alkali metal sulfide.

The polymerization can be carried out by a step-wise polymerizationprocess. The first polymerization step can include introducing thedihaloaromatic compound to a reactor, and subjecting the dihaloaromaticcompound to a polymerization reaction in the presence of water at atemperature of from about 180° C. to about 235° C., or from about 200°C. to about 230° C., and continuing polymerization until the conversionrate of the dihaloaromatic compound attains to not less than about 50mol % of the theoretically necessary amount.

In a second polymerization step, water is added to the reaction slurryso that the total amount of water in the polymerization system isincreased to about 7 moles, or to about 5 moles, per mole of theeffective amount of the charged alkali metal sulfide. Following, thereaction mixture of the polymerization system can be heated to atemperature of from about 250° C. to about 290° C., from about 255° C.to about 280° C., or from about 260° C. to about 270° C. and thepolymerization can continue until the melt viscosity of the thus formedpolymer is raised to the desired final level of the polyarylene sulfide.The duration of the second polymerization step can be, e.g., from about0.5 to about 20 hours, or from about 1 to about 10 hours.

The polyarylene sulfide may be linear, semi-linear, branched orcrosslinked. A linear polyarylene sulfide includes as the mainconstituting unit the repeating unit of —(Ar—S)—. In general, a linearpolyarylene sulfide may include about 80 mol % or more of this repeatingunit. A linear polyarylene sulfide may include a small amount of abranching unit or a cross-linking unit, but the amount of branching orcross-linking units may be less than about 1 mol % of the total monomerunits of the polyarylene sulfide. A linear polyarylene sulfide polymermay be a random copolymer or a block copolymer containing theabove-mentioned repeating unit.

A semi-linear polyarylene sulfide may be utilized that may have across-linking structure or a branched structure provided by introducinginto the polymer a small amount of one or more monomers having three ormore reactive functional groups. For instance between about 1 mol % andabout 10 mol % of the polymer may be formed from monomers having threeor more reactive functional groups. Methods that may be used in makingsemi-linear polyarylene sulfide are generally known in the art. By wayof example, monomer components used in forming a semi-linear polyarylenesulfide can include an amount of polyhaloaromatic compounds having 2 ormore halogen substituents per molecule which can be utilized inpreparing branched polymers. Such monomers can be represented by theformula R′X_(n), where each X is selected from chlorine, bromine, andiodine, n is an integer of 3 to 6, and R′ is a polyvalent aromaticradical of valence n which can have up to about 4 methyl substituents,the total number of carbon atoms in R′ being within the range of 6 toabout 16. Examples of some polyhaloaromatic compounds having more thantwo halogens substituted per molecule that can be employed in forming asemi-linear polyarylene sulfide include 1,2,3-trichlorobenzene,1,2,4-trichlorobenzene, 1,3-dichloro-5-bromobenzene,1,2,4-triiodobenzene, 1,2,3,5-tetrabromobenzene, hexachlorobenzene,1,3,5-trichloro-2,4,6-trimethylbenzene, 2,2′,4,4′-tetrachlorobiphenyl,2,2′,5,5′-tetra-iodobiphenyl,2,2′,6,6′-tetrabromo-3,3′,5,5′-tetramethylbiphenyl,1,2,3,4-tetrachloronaphthalene, 1,2,4-tribromo-6-methylnaphthalene, andthe like, and mixtures thereof.

Following polymerization, the polyarylene sulfide may be washed withliquid media. For instance, the polyarylene sulfide may be washed withwater and/or organic solvents that will not decompose the polyarylenesulfide including, without limitation, acetone, N-methyl-2-pyrrolidone,a salt solution, and/or an acidic media such as acetic acid orhydrochloric acid prior to combination with other components whileforming the mixture. The polyarylene sulfide can be washed in asequential manner that is generally known to persons skilled in the art.Washing with an acidic solution or a salt solution may reduce thesodium, lithium or calcium metal ion end group concentration from about2000 ppm to about 100 ppm.

A polyarylene sulfide can be subjected to a hot water washing process.The temperature of a hot water wash can be at or above about 100° C.,for instance higher than about 120° C., higher than about 150° C., orhigher than about 170° C.

The polymerization reaction apparatus for forming the polyarylenesulfide is not especially limited, although it is typically desired toemploy an apparatus that is commonly used in formation of high viscosityfluids. Examples of such a reaction apparatus may include a stirringtank type polymerization reaction apparatus having a stirring devicethat has a variously shaped stirring blade, such as an anchor type, amultistage type, a spiral-ribbon type, a screw shaft type and the like,or a modified shape thereof. Further examples of such a reactionapparatus include a mixing apparatus commonly used in kneading, such asa kneader, a roll mill, a Banbury mixer, etc. Following polymerization,the molten polyarylene sulfide may be discharged from the reactor,typically through an extrusion orifice fitted with a die of desiredconfiguration, cooled, and collected. Commonly, the polyarylene sulfidemay be discharged through a perforated die to form strands that aretaken up in a water bath, pelletized and dried. The polyarylene sulfidemay also be in the form of a strand, granule, or powder.

The thermoplastic composition may include the polyarylene sulfidecomponent (which also encompasses a blend of polyarylene sulfides) in anamount from about 10 wt. % to about 99 wt. % by weight of thecomposition, for instance from about 20% wt. % to about 90 wt. % byweight of the composition.

The polyarylene sulfide may be of any suitable molecular weight and meltviscosity, generally depending upon the final application intended forthe thermoplastic composition. For instance, the melt viscosity of thepolyarylene sulfide may be a low viscosity polyarylene sulfide, having amelt viscosity of less than about 500 poise, a medium viscositypolyarylene sulfide, having a melt viscosity of between about 500 poiseand about 1500 poise, or a high melt viscosity polyarylene sulfide,having a melt viscosity of greater than about 1,500 poise, as determinedin accordance with ISO Test No. 11443 at a shear rate of 1200 s⁻¹ and ata temperature of 310° C.

According to one embodiment, the polyarylene sulfide can befunctionalized to further encourage bond formation between thepolyarylene sulfide and the impact modifier, which can further improvedistribution of the impact modifier throughout the composition andfurther prevent phase separation. For instance, a polyarylene sulfidecan be further treated following formation with a carboxyl, acidanhydride, amine, isocyanate or other functional group-containingmodifying compound to provide a functional terminal group on thepolyarylene sulfide. By way of example, a polyarylene sulfide can bereacted with a modifying compound containing a mercapto group or adisulfide group and also containing a reactive functional group. In oneembodiment, the polyarylene sulfide can be reacted with the modifyingcompound in an organic solvent. In another embodiment, the polyarylenesulfide can be reacted with the modifying compound in the molten state.

In one embodiment, a disulfide compound containing the desiredfunctional group can be incorporated into the thermoplastic compositionformation process, and the polyarylene sulfide can be functionalized inconjunction with formation of the composition. For instance, a disulfidecompound containing the desired reactive functional groups can be addedto the melt extruder in conjunction with the polyarylene sulfide or atany other point prior to or in conjunction with the addition of thecrosslinking agent.

Reaction between the polyarylene sulfide polymer and the reactivelyfunctionalized disulfide compound can include chain scission of thepolyarylene sulfide polymer that can decrease melt viscosity of thepolyarylene sulfide. In one embodiment, a higher melt viscositypolyarylene sulfide having low halogen content can be utilized as astarting polymer. Following reactive functionalization of thepolyarylene sulfide polymer by use of a functional disulfide compound, arelatively low melt viscosity polyarylene sulfide with low halogencontent can be formed. Following this chain scission, the melt viscosityof the polyarylene sulfide can be suitable for further processing, andthe overall halogen content of the low melt viscosity polyarylenesulfide can be quite low. A thermoplastic composition that exhibitsexcellent strength and degradation resistance in addition to low halogencontent can be advantageous as low halogen content polymeric materialsare becoming increasingly desired due to environmental concerns. In oneembodiment, the thermoplastic composition can have a halogen content ofless than about 1000 ppm, less than about 900 ppm, less than about 600ppm, or less than about 400 ppm as determined according to an elementalanalysis using Parr Bomb combustion followed by Ion Chromatography.

The disulfide compound can generally have the structure of:

R¹—S—S—R²

wherein R¹ and R² may be the same or different and are hydrocarbongroups that independently include from 1 to about 20 carbons. Forinstance, R¹ and R² may be an alkyl, cycloalkyl, aryl, or heterocyclicgroup. R¹ and R¹ may include reactive functionality at terminal end(s)of the disulfide compound. For example, at least one of R¹ and R² mayinclude a terminal carboxyl group, hydroxyl group, a substituted ornon-substituted amino group, a nitro group, or the like. In general, thereactive functionality can be selected such that the reactivelyfunctionalized polyarylene sulfide can react with the impact modifier.For example, when considering an epoxy-terminated impact modifier, thedisulfide compound can include carboxyl and/or amine functionality.

Examples of disulfide compounds including reactive terminal groups asmay be encompassed herein may include, without limitation,2,2′-diaminodiphenyl disulfide, 3,3′-diaminodiphenyl disulfide,4,4′-diaminodiphenyl disulfide, dibenzyl disulfide, dithiosalicyclicacid, dithioglycolic acid, α,α′-dithiodilactic acid, β,β′-dithiodilacticacid, 3,3′-dithiodipyridine, 4,4′dithiomorpholine,2,2′-dithiobis(benzothiazole), 2,2′-dithiobis(benzimidazole),2,2′-dithiobis(benzoxazole) and 2-(4′-morpholinodithio)benzothiazole.

The ratio of the amount of the polyarylene sulfide to the amount of thedisulfide compound can be from about 1000:1 to about 10:1, from about500:1 to about 20:1, or from about 400:1 to about 30:1.

In addition to the polyarylene sulfide polymer, the composition alsoincludes an impact modifier. More specifically, the impact modifier canbe an olefinic copolymer or terpolymer. For instance, the impactmodifier can include ethylenically unsaturated monomer units have fromabout 4 to about 10 carbon atoms.

The impact modifier can be modified to include functionalization so asto react with the crosslinking agent. For instance, the impact modifiercan be modified with a mole fraction of from about 0.01 to about 0.5 ofone or more of the following: an α, β unsaturated dicarboxylic acid orsalt thereof having from about 3 to about 8 carbon atoms; an α, βunsaturated carboxylic acid or salt thereof having from about 3 to about8 carbon atoms; an anhydride or salt thereof having from about 3 toabout 8 carbon atoms; a monoester or salt thereof having from about 3 toabout 8 carbon atoms; a sulfonic acid or a salt thereof; an unsaturatedepoxy compound having from about 4 to about 11 carbon atoms. Examples ofsuch modification functionalities include maleic anhydride, fumaricacid, maleic acid, methacrylic acid, acrylic acid, and glycidylmethacrylate. Examples of metallic acid salts include the alkaline metaland transitional metal salts such as sodium, zinc, and aluminum salts.

A non-limiting listing of impact modifiers that may be used includeethylene-acrylic acid copolymer, ethylene-maleic anhydride copolymers,ethylene-alkyl (meth)acrylate-maleic anhydride terpolymers,ethylene-alkyl (meth)acrylate-glycidyl (meth)acrylate terpolymers,ethylene-acrylic ester-methacrylic acid terpolymer, ethylene-acrylicester-maleic anhydride terpolymer, ethylene-methacrylic acid-methacrylicacid alkaline metal salt (ionomer) terpolymers, and the like. In oneembodiment, for instance, an impact modifier can include a randomterpolymer of ethylene, methylacrylate, and glycidyl methacrylate. Theterpolymer can have a glycidyl methacrylate content of from about 5% toabout 20%, such as from about 6% to about 10%. The terpolymer may have amethylacrylate content of from about 20% to about 30%, such as about24%.

According to one embodiment, the impact modifier may be a linear orbranched, homopolymer or copolymer (e.g., random, graft, block, etc.)containing epoxy functionalization, e.g., terminal epoxy groups,skeletal oxirane units, and/or pendent epoxy groups. For instance, theimpact modifier may be a copolymer including at least one monomercomponent that includes epoxy functionalization. The monomer units ofthe impact modifier may vary. In one embodiment, for example, the impactmodifier can include epoxy-functional methacrylic monomer units. As usedherein, the term methacrylic generally refers to both acrylic andmethacrylic monomers, as well as salts and esters thereof, e.g.,acrylate and methacrylate monomers. Epoxy-functional methacrylicmonomers as may be incorporated in the impact modifier may include, butare not limited to, those containing 1,2-epoxy groups, such as glycidylacrylate and glycidyl methacrylate. Other suitable epoxy-functionalmonomers include allyl glycidyl ether, glycidyl ethacrylate, andglycidyl itoconate.

Other monomer units may additionally or alternatively be a component ofthe impact modifier. Examples of other monomers may include, forexample, ester monomers, olefin monomers, amide monomers, etc. In oneembodiment, the impact modifier can include at least one linear orbranched α-olefin monomer, such as those having from 2 to 20 carbonatoms, or from 2 to 8 carbon atoms. Specific examples include ethylene;propylene; 1-butene; 3-methyl-1-butene; 3,3-dimethyl-1-butene;1-pentene; 1-pentene with one or more methyl, ethyl or propylsubstituents; 1-hexene with one or more methyl, ethyl or propylsubstituents; 1-heptene with one or more methyl, ethyl or propylsubstituents; 1-octene with one or more methyl, ethyl or propylsubstituents; 1-nonene with one or more methyl, ethyl or propylsubstituents; ethyl, methyl or dimethyl-substituted 1-decene;1-dodecene; and styrene.

Monomers included in an impact modifier that includes epoxyfunctionalization can include monomers that do not include epoxyfunctionalization, as long as at least a portion of the monomer units ofthe polymer are epoxy functionalized.

In one embodiment, the impact modifier can be a terpolymer that includesepoxy functionalization. For instance, the impact modifier can include amethacrylic component that includes epoxy functionalization, an a-olefincomponent, and a methacrylic component that does not include epoxyfunctionalization. For example, the impact modifier may bepoly(ethylene-co-methylacrylate-co-glycidyl methacrylate), which has thefollowing structure:

wherein, a, b, and c are 1 or greater.

In another embodiment the impact modifier can be a random copolymer ofethylene, ethyl acrylate and maleic anhydride having the followingstructure:

wherein x, y and z are 1 or greater.

The relative proportion of the various monomer components of acopolymeric impact modifier is not particularly limited. For instance,in one embodiment, the epoxy-functional methacrylic monomer componentscan form from about 1 wt. % to about 25 wt. %, or from about 2 wt. % toabout 20 wt % of a copolymeric impact modifier. An a-olefin monomer canform from about 55 wt. % to about 95 wt. %, or from about 60 wt. % toabout 90 wt. %, of a copolymeric impact modifier. When employed, othermonomeric components (e.g., a non-epoxy functional methacrylic monomers)may constitute from about 5 wt. % to about 35 wt. %, or from about 8 wt.% to about 30 wt. %, of a copolymeric impact modifier.

An impact modifier may be formed according to standard polymerizationmethods as are generally known in the art. For example, a monomercontaining polar functional groups may be grafted onto a polymerbackbone to form a graft copolymer. Alternatively, a monomer containingfunctional groups may be copolymerized with a monomer to form a block orrandom copolymer using known free radical polymerization techniques,such as high pressure reactions, Ziegler-Natta catalyst reactionsystems, single site catalyst (e.g., metallocene) reaction systems, etc.

Alternatively, an impact modifier may be obtained on the retail market.By way of example, suitable compounds for use as an impact modifier maybe obtained from Arkema under the name Lotader®.

The molecular weight of the impact modifier can vary widely. Forexample, the impact modifier can have a number average molecular weightfrom about 7,500 to about 250,000 grams per mole, in some embodimentsfrom about 15,000 to about 150,000 grams per mole, and in someembodiments, from about 20,000 to 100,000 grams per mole, with apolydispersity index typically ranging from 2.5 to 7.

In general, the impact modifier may be present in the composition in anamount from about 0.05% to about 40% by weight, from about 0.05% toabout 37% by weight, or from about 0.1% to about 35% by weight.

Referring again to FIG. 5, the impact modifier can be added to thecomposition in conjunction with the polyarylene sulfide at the main feedthroat 314 of the melt processing unit. This is not a requirement of thecomposition formation process, however, and in other embodiments, theimpact modifier can be added downstream of the main feed throat. Forinstance, the impact modifier may be added at a location downstream fromthe point at which the polyarylene sulfide is supplied to the meltprocessing unit, but yet prior to the melting section, i.e., that lengthof the melt processing unit in which the polyarylene sulfide becomesmolten. In another embodiment, the impact modifier may be added at alocation downstream from the point at which the polyarylene sulfidebecomes molten.

If desired, one or more distributive and/or dispersive mixing elementsmay be employed within the mixing section of the melt processing unit.Suitable distributive mixers for single screw extruders may include butare not limited to, for instance, Saxon, Dulmage, Cavity Transfermixers, etc. Likewise, suitable dispersive mixers may include but arenot limited to Blister ring, Leroy/Maddock, CRD mixers, etc. As is wellknown in the art, the mixing may be further improved by using pins inthe barrel that create a folding and reorientation of the polymer melt,such as those used in Buss Kneader extruders, Cavity Transfer mixers,and Vortex Intermeshing Pin mixers.

In addition to the polyarylene sulfide and the impact modifier, thethermoplastic composition can include a crosslinking agent. Thecrosslinking agent can be a polyfunctional compound or combinationthereof that can react with functionality of the impact modifier to formcrosslinks within and among the polymer chains of the impact modifier.In general, the crosslinking agent can be a non-polymeric compound,i.e., a molecular compound that includes two or more reactivelyfunctional terminal moieties linked by a bond or a non-polymeric(non-repeating) linking component. By way of example, the crosslinkingagent can include but is not limited to di-epoxides, poly-functionalepoxides, diisocyanates, polyisocyanates, polyhydric alcohols,water-soluble carbodiimides, diamines, diaminoalkanes, polyfunctionalcarboxylic acids, diacid halides, and so forth. For instance, whenconsidering an epoxy-functional impact modifier, a non-polymericpolyfunctional carboxylic acid or amine can be utilized as acrosslinking agent.

Specific examples of polyfunctional carboxylic acid crosslinking agentscan include, without limitation, isophthalic acid, terephthalic acid,phthalic acid, 1,2-di(p-carboxyphenyl)ethane, 4,4′-dicarboxydiphenylether, 4,4′-bisbenzoic acid, 1,4- or 1,5-naphthalene dicarboxylic acids,decahydronaphthalene dicarboxylic acids, norbornene dicarboxylic acids,bicyclooctane dicarboxylic acids, 1,4-cyclohexanedicarboxylic acid (bothcis and trans), 1,4-hexylenedicarboxylic acid, adipic acid, azelaicacid, dicarboxyl dodecanoic acid, succinic acid, maleic acid, glutaricacid, suberic acid, azelaic acid and sebacic acid. The correspondingdicarboxylic acid derivatives, such as carboxylic acid diesters havingfrom 1 to 4 carbon atoms in the alcohol radical, carboxylic acidanhydrides or carboxylic acid halides may also be utilized.

Exemplary diols useful as crosslinking agents can include, withoutlimitation, aliphatic diols such as ethylene glycol, 1,2-propyleneglycol, 1,3-propylene glycol, 2,2-dimethyl-1,3-propane diol,2-ethyl-2-methyl-1,3-propane diol, 1,4-butane diol, 1,4-but-2-ene diol,1,3-1,5-pentane diol, 1,5-pentane diol, dipropylene glycol,2-methyl-1,5-pentane diol, and the like. Aromatic diols can also beutilized such as, without limitation, hydroquinone, catechol,resorcinol, methylhydroquinone, chlorohydroquinone, bisphenol A,tetrachlorobisphenol A, phenolphthalein, and the like. Exemplarycycloaliphatic diols as may be used include a cycloaliphatic moiety, forexample 1,6-hexane diol, dimethanol decalin, dimethanol bicyclooctane,1,4-cyclohexane dimethanol (including its cis- and trans-isomers),triethylene glycol, 1,10-decanediol, and the like.

Exemplary diamines that may be utilized as crosslinking agents caninclude, without limitation, isophorone-diamine, ethylenediamine, 1,2-,1,3-propylene-diamine, N-methyl-1,3-propylene-diamine,N,N′-dimethyl-ethylene-diamine, and aromatic diamines, such as, forexample, 2,4- and 2,6-toluoylene-diamine, 3,5-diethyl-2,4- and/or-2,6-toluoylene-diamine, and primary ortho- di-, tri- and/ortetra-alkyl-substituted 4,4′-diaminodiphenyl-methanes. (cyclo)aliphaticdiamines, such as, for example, isophorone-diamine, ethylenediamine,1,2-, 1,3-propylene-diamine, N-methyl-1,3-propylene-diamine,N,N′-dimethyl-ethylene-diamine, and aromatic diamines, such as, forexample, 2,4- and 2,6-toluoylene-diamine, 3,5-diethyl-2,4- and/or-2,6-toluoylene-diamine, and primary ortho- di-, tri- and/ortetra-alkyl-substituted 4,4′-diaminodiphenyl-methanes.

In one embodiment, the composition can include a disulfide-freecrosslinking agent. For example, the crosslinking agent can includecarboxyl and/or amine functionality with no disulfide group that mayreact with the polyarylene sulfide. A crosslinking agent that isdisulfide-free can be utilized so as to avoid excessive chain scissionof the polyarylene sulfide by the crosslinking agent during formation ofthe composition. It should be understood, however, that the utilizationof a disulfide-free crosslinking agent does not in any way limit theutilization of a reactively functionalized disulfide compound forfunctionalizing the polyarylene sulfide. For instance, in oneembodiment, the composition can be formed according to a process thatincludes addition of a reactively functionalized disulfide compound tothe melt processing unit that can reactively functionalize thepolyarylene sulfide. The crosslinking agent utilized in this embodimentcan then be a disulfide-free crosslinking agent that can includefunctionality that is reactive with the impact modifier as well as withthe reactively functionalized polyarylene sulfide. Thus, the compositioncan be highly crosslinked without excessive scission of the polyarylenesulfide polymer chains.

In another embodiment the crosslinking agent and the polyarylene sulfidefunctionalization compound (when present) can be selected so as toencourage chain scission of the polyarylene sulfide. This may bebeneficial, for instance, which chain scission is desired to decreasethe melt viscosity of the polyarylene sulfide polymer.

The thermoplastic composition may generally include the crosslinkingagent in an amount from about 0.05 wt. % to about 2 wt. % by weight ofthe thermoplastic composition, from about 0.07 wt. % to about 1.5 wt. %by weight of the thermoplastic composition, or from about 0.1 wt. % toabout 1.3 wt. %.

The crosslinking agent can be added to the melt processing unitfollowing mixing of the polyarylene sulfide and the impact modifier. Forinstance, as illustrated in FIG. 5, the crosslinking agent can be addedto the composition at a downstream location 316 following addition ofpolyarylene sulfide and the impact modifier (either together orseparately) to the melt processing unit. This can ensure that the impactmodifier has become dispersed throughout the polyarylene sulfide priorto addition of the crosslinking agent.

To help encourage distribution of the impact modifier throughout themelt prior to addition of the crosslinking agent, a variety of differentparameters may be selectively controlled. For example, the ratio of thelength (“L”) to diameter (“D”) of a screw of the melt processing unitmay be selected to achieve an optimum balance between throughput andimpact modifier distribution. For example, the L/D value after the pointat which the impact modifier is supplied may be controlled to encouragedistribution of the impact modifier. More particularly, the screw has ablending length (“L_(B)”) that is defined from the point at which boththe impact modifier and the polyarylene sulfide are supplied to the unit(i.e., either where they are both supplied in conjunction with oneanother or the point at which the latter of the two is supplied) to thepoint at which the crosslinking agent is supplied, the blending lengthgenerally being less than the total length of the screw. For example,when considering a melt processing unit that has an overall L/D of 40,the L_(B)/D ratio of the screw can be from about 1 to about 36, in someembodiments from about 4 to about 20, and in some embodiments, fromabout 5 to about 15. In one embodiment, the L/L_(B) ratio can be fromabout 40 to about 1.1, from about 20 to about 2, or from about 10 toabout 5.

Following addition of the crosslinking agent, the composition can bemixed to distribute the crosslinking agent throughout the compositionand encourage reaction between the crosslinking agent, the impactmodifier, and, in one embodiment, with the polyarylene sulfide.

The composition can also include one or more additives as are generallyknown in the art. For example, one or more fillers can be included inthe composition. One or more fillers may generally be included in thecomposition an amount of from about 5 wt. % to about 70 wt. %, or fromabout 20 wt. % to about 65 wt. % by weight of the composition.

The filler can be added to the thermoplastic composition according tostandard practice. For instance, the filler can be added to thecomposition at a downstream location of the melt processing unit. Forexample, a filler may be added to the composition in conjunction withthe addition of the crosslinking agent. However, this is not arequirement of a formation process and the filler can be addedseparately from the crosslinking agent and either upstream or downstreamof the point of addition of the crosslinking agent. In addition, afiller can be added at a single feed location, or may be split and addedat multiple feed locations along the melt processing unit.

A filler can be an electrically conductive filler such as, withoutlimitation, carbon black, graphite, graphene, carbon fiber, carbonnanotubes, a metal powder, and so forth. In those embodiments in whichthe thermoplastic composition includes electrically conductive fillers,for instance when the thermoplastic composition is utilized in forming afuel line, adequate electrically conductive filler can be included suchthat the composition has a volume specific resistance of equal to orless than about 10 ⁹ ohms cm.

In one embodiment, a fibrous filler can be included in the thermoplasticcomposition. The fibrous filler may include one or more fiber typesincluding, without limitation, polymer fibers, glass fibers, carbonfibers, metal fibers, basalt fibers, and so forth, or a combination offiber types. In one embodiment, the fibers may be chopped fibers,continuous fibers, or fiber rovings (tows).

Fiber sizes can vary as is known in the art. In one embodiment, thefibers can have an initial length of from about 3 mm to about 5 mm. Inanother embodiment, for instance when considering a pultrusion process,the fibers can be continuous fibers. Fiber diameters can vary dependingupon the particular fiber used. The fibers, for instance, can have adiameter of less than about 100 μm, such as less than about 50 μm. Forinstance, the fibers can be chopped or continuous fibers and can have afiber diameter of from about 5 μm to about 50 μm, such as from about 5μm to about 15 μm.

The fibers may be pretreated with a sizing as is generally known. In oneembodiment, the fibers may have a high yield or small K numbers. The towis indicated by the yield or K number. For instance, glass fiber towsmay have 50 yield and up, for instance from about 115 yield to about1200 yield.

Other fillers can alternatively be utilized or may be utilized inconjunction with a fibrous filler. For instance, a particulate fillercan be incorporated in the composition. In general, particulate fillerscan encompass any particulate material having a median particle size ofless than about 750 μm, for instance less than about 500 μm, or lessthan about 100 μm. In one embodiment, a particulate filler can have amedian particle size in the range of from about 3 μm to about 20 μm. Inaddition, a particulate filler can be solid or hollow, as is known.Particulate fillers can also include a surface treatment, as is known inthe art.

Particulate fillers can encompass one or more mineral fillers. Forinstance, the thermoplastic composition can include one or more mineralfillers in an amount of from about 1 wt. % to about 60 wt. % of thecomposition. Mineral fillers may include, without limitation, silica,quartz powder, silicates such as calcium silicate, aluminum silicate,kaolin, talc, mica, clay, diatomaceous earth, wollastonite, calciumcarbonate, and so forth.

When incorporating multiple fillers, for instance an electricallyconductive filler, a particulate filler and a fibrous filler, thefillers may be added together or separately to the melt processing unit.For instance, a particulate filler can be added to the main feed withthe polyarylene sulfide or downstream prior to addition of a fibrousfiller, and a fibrous filler can be added further downstream of theaddition point of the particulate filler. In general, a fibrous fillercan be added downstream of any other fillers such as a particulatefiller, though this is not a requirement.

In one embodiment, the thermoplastic composition can include a UVstabilizer as an additive. For instance, the thermoplastic compositioncan include a UV stabilizer in an amount of between about 0.5 wt. % andabout 15 wt. %, between about 1 wt. % and about 8 wt. %, or betweenabout 1.5 wt. % and about 7 wt. % of a UV stabilizer. One particularlysuitable UV stabilizer that may be employed is a hindered amine UVstabilizer. Suitable hindered amine UV stabilizer compounds may bederived from a substituted piperidine, such as alkyl-substitutedpiperidyl, piperidinyl, piperazinone, alkoxypiperidinyl compounds, andso forth. For example, the hindered amine may be derived from a2,2,6,6-tetraalkylpiperidinyl. The hindered amine may, for example, bean oligomeric or polymeric compound having a number average molecularweight of about 1,000 or more, in some embodiments from about 1000 toabout 20,000, in some embodiments from about 1500 to about 15,000, andin some embodiments, from about 2000 to about 5000. Such compoundstypically contain at least one 2,2,6,6-tetraalkylpiperidinyl group(e.g., 1 to 4) per polymer repeating unit. One particularly suitablehigh molecular weight hindered amine is commercially available fromClariant under the designation Hostavin® N30 (number average molecularweight of 1200). Another suitable high molecular weight hindered amineis commercially available from Adeka Palmarole SAS under the designationADK STAB® LA-63 and ADK STAB® LA-68.

In addition to the high molecular hindered amines, low molecular weighthindered amines may also be employed. Such hindered amines are generallymonomeric in nature and have a molecular weight of about 1000 or less,in some embodiments from about 155 to about 800, and in someembodiments, from about 300 to about 800.

Other suitable UV stabilizers may include UV absorbers, such asbenzotriazoles or benzopheones, which can absorb UV radiation.

An additive that may be included in a thermoplastic composition is oneor more colorants as are generally known in the art. For instance, thecomposition can include from about 0.1 wt. % to about 10 wt. %, or fromabout 0.2 wt. % to about 5 wt. % of one or more colorants. As utilizedherein, the term “colorant” generally refers to any substance that canimpart color to a material. Thus, the term “colorant” encompasses bothdyes, which exhibit solubility in an aqueous solution, and pigments,that exhibit little or no solubility in an aqueous solution.

Examples of dyes that may be used include, but are not limited to,disperse dyes. Suitable disperse dyes may include those described in“Disperse Dyes” in the Color Index, 3^(rd) edition. Such dyes include,for example, carboxylic acid group-free and/or sulfonic acid group-freenitro, amino, aminoketone, ketoninime, methine, polymethine,diphenylamine, quinoline, benzimidazole, xanthene, oxazine and coumarindyes, anthraquinone and azo dyes, such as mono- or di-azo dyes. Dispersedyes also include primary red color disperse dyes, primary blue colordisperse dyes, and primary yellow color dyes

Pigments that can be incorporated in a thermoplastic composition caninclude, without limitation, organic pigments, inorganic pigments,metallic pigments, phosphorescent pigments, fluorescent pigments,photochromic pigments, thermochromic pigments, iridescent pigments, andpearlescent pigments. The specific amount of pigment can depends uponthe desired final color of the product. Pastel colors are generallyachieved with the addition of titanium dioxide white or a similar whitepigment to a colored pigment.

Other additives that can be included in the thermoplastic compositioncan encompass, without limitation, antimicrobials, lubricants, pigmentsor other colorants, impact modifiers, antioxidants, stabilizers (e.g.,heat stabilizers including organophosphites such as Doverphos® productsavailable from Dover Chemical Corporation), surfactants, flow promoters,solid solvents, and other materials added to enhance properties andprocessability. Such optional materials may be employed in thethermoplastic composition in conventional amounts and according toconventional processing techniques, for instance through addition to thethermoplastic composition at the main feed throat. Beneficially, thethermoplastic composition can exhibit desirable characteristics withoutthe addition of plasticizers. For instance, the composition can be freeof plasticizers such as phthalate esters, trimellitates, sebacates,adipates, gluterates, azelates, maleates, benzoates, and so forth.

Following addition of all components to the thermoplastic composition,the composition is thoroughly mixed in the remaining section(s) of theextruder and extruded through a die. The final extrudate can bepelletized and stored prior to formation of a fuel line or may bedirectly fed to a formation process.

Any known process can be employed without any particular limitation formanufacturing a fuel line. For instance, when considering formation of amulti-layer fuel line, the layers forming the wall of the fuel line canbe form by an extrusion process or one or more other conventionalprocesses, such as, for example, co-extrusion, dry lamination, sandwichlamination, coextrusion coating, and so forth. Adjacent layers can beformed simultaneously by a co-extrusion method , i.e., extruding themolten materials for those layers concentrically and simultaneously, andcausing them to adhere to each other. Co-extrusion may be performed byusing any known apparatus including co-extrusion heads. In general,co-extrusion can be used in forming a multi-layer fuel line having fromtwo to about six layers.

By way of example, in forming a three-layered fuel line 70 asillustrated in FIG. 4, the thermoplastic composition, a polyamidecomposition, and a thermoplastic elastomer composition can be separatelyfed into three different extruders. The separate extrusion melts fromthose three extruders can then be introduced into one die underpressure. While producing three different tubular melt flows, those meltflows can be combined in the die in such a manner that the melt flow ofthe thermoplastic composition forms the inner layer 71, that of thepolyamide composition forms the intermediate layer 72, and that of thethermoplastic elastomer composition forms the outer layer 73, and thethus-combined melt flows are co-extruded out of the die to produce athree-layered fuel line 70.

Co-extrusion is not a requirement of an extrusion formation process,however, and in other embodiments an outer layer can be formed on apre-formed layer(s). For instance, an outer layer can be formed byextrusion about one or more pre-formed inner layers (inner wall layer,or inner and intermediate wall layers), though any other method can alsobe employed.

A fuel line or a layer of a fuel line can be formed according to anextrusion process. For example, an extrusion process utilizing a simpleor barrier type screw can be utilized and, in one embodiment, a mixingtip need not be utilized in the process. The compression ratio for anextrusion process can be between about 2.5:1 and about 4:1. Forinstance, the compression ratio can be about 25% feed, about 25%transition, and about 50% metering. The ratio of the barrel length tothe barrel diameter (L/D) can be from about 16 to about 24. An extrusionprocess can also utilize other standard components as are known in theart such as, for example, breaker plates, screen packs, adapters, a die,and a vacuum tank. The vacuum tank can generally include a sizingsleeve/calibration ring, tank seals.

When forming a fuel line according to an extrusion process, thethermoplastic composition can first be dried, for instance at atemperature of from about 90° C. to about 100° C. for about three hours.It may be beneficial to avoid drying for an extensive length of time soas to avoid discoloration of the composition. The extruder can exhibitdifferent temperatures in different zones, as is known. For instance, inone embodiment, the extruder can include at least four zones, with thetemperature of the first zone from about 276° C. to about 288° C., thetemperature of the second zone from about 282° C. to about 299° C., thetemperature of the third zone from about 282° C. to about 299° C., andthe temperature of the fourth zone from about 540° C. to about 580° C.Meanwhile, the temperature of the die can be from about 293° C. to about310° C., and the vacuum tank water can be from about 20° C. to about 50°C.

Typically, the head pressure can be from about 100 pounds per squareinch (psi) (about 690 kPa) to about 1000 psi (about 6900 kPa), and thehead pressure can be adjusted to achieve a stable melt flow, as isknown. For instance, the head pressure can be reduced by increasing theextruder zone temperature, by increasing the extruder screw rotationsper minute, reducing the screen pack mesh size and/or the number ofscreens. In general, the line speed can be from about 4 meters perminute to about 15 meters per minute. Of course, the actual line speedcan depend upon the final dimension of the fuel line, the aesthetics ofthe final product and process stability.

The die swell during an extrusion process can generally be negligible. Adraw down of about 1.2 to about 1.7 can generally be utilized, as ahigher draw down can negatively affect the final properties of the fuelline, depending on other processing conditions. Die drool can generallybe avoided by drying the resin adequately prior to extrusion as well asby maintaining the melt temperature at less than about 304° C.

In one embodiment, a fuel line or a layer of a fuel line extruded fromthe thermoplastic composition can have a wall thickness of between about0.5 millimeters to about 5 millimeters, though fuel lines having largerwall thickness can be formed from the composition as desired. Thecalibration ring inner diameter can decide the outer diameter of thefuel line and will generally be less than the outer diameter of the die,as is known. The inner diameter of the fuel line can be utilized todetermine the desired outer diameter of the mandrel and the line speed,as is known.

A corrugated fuel line having a corrugated portion along at least a partof its wall length can be formed in one embodiment by extruding a moltenresin into a smooth tube and forming a corrugated portion in its wall byan appropriate corrugating mold or like device, though any other methodcan also be employed.

A fuel line can also be formed through utilization of a blow moldingprocess to form one or more layers of a fuel line. By way of example,FIG. 6 presents a schematic illustration of one method as may beutilized in forming a fuel line according to a continuous blow moldingprocess. In a continuous process, a stationary extruder (not shown) canplasticize the molten thermoplastic composition through a head to form acontinuous parison 601. An accumulator 605 can be used to support theparison and prevent sagging prior to molding. The parison may be fed toa mold formed of articulated sections 602, 603 that travel inconjunction with the continuous parison on a mold conveyor assembly 604.Air under pressure is applied to the parison to blow mold thethermoplastic composition within the mold. After the thermoplasticcomposition has been molded and sufficiently cooled within the mold asthe mold and thermoplastic composition travel together, the moldsegments are separated from one another and the formed line 606 isremoved from the conveyor and taken up, as on a take-up reel (notshown). The fuel line can then be cut to the desired length form theline 606 thus formed.

Additional layers can be formed on a blow molded layer according to anextrusion process, for instance to form an outer layer on a pre-formedlayer, or according to a second blow molding process, for instance toform an inner layer on a pre-formed layer.

Surface treatments can be carried out on pre-formed layers prior toformation of or attachment to an adjacent layer so as to improveadhesion between adjacent layers. For example, plasma treatment orcorona treatment as is generally known can be carried out to improveadhesion between adjacent layers of a multi-layer fuel line.

Embodiments of the present disclosure are illustrated by the followingexamples that are merely for the purpose of illustration of embodimentsand are not to be regarded as limiting the scope of the invention or themanner in which it may be practiced. Unless specifically indicatedotherwise, parts and percentages are given by weight.

Formation and Test Methods

Injection Molding Process: Tensile bars are injection molded to ISO527-1 specifications according to standard ISO conditions.

Melt Viscosity: All materials are dried for 1.5 hours at 150° C. undervacuum prior to testing. The melt viscosity is measured on a capillaryrheometer at 316° C. and 400 sec⁻¹ with the viscosity measurement takenafter five minutes of constant shear.

Tensile Properties: Tensile properties including tensile modulus, yieldstress, yield strain, strength at break, elongation at yield, elongationat break, etc. are tested according to ISO Test No. 527 (technicallyequivalent to ASTM D638). Modulus, strain, and strength measurements aremade on the same test strip sample having a length of 80 mm, thicknessof 10 mm, and width of 4 mm. The testing temperature is 23° C., and thetesting speeds are 5 or 50 mm/min.

Flexural Properties: Flexural properties including flexural strength andflexural modulus are tested according to ISO Test No. 178 (technicallyequivalent to ASTM D790). This test is performed on a 64 mm supportspan. Tests are run on the center portions of uncut ISO 3167multi-purpose bars. The testing temperature is 23° C. and the testingspeed is 2 mm/min.

Deflection Temperature Under Load (“DTUL”): The deflection under loadtemperature was determined in accordance with ISO Test No. 75-2(technically equivalent to ASTM D648-07). More particularly, a teststrip sample having a length of 80 mm, thickness of 10 mm, and width of4 mm was subjected to an edgewise three-point bending test in which thespecified load (maximum outer fibers stress) was 1.8 Megapascals. Thespecimen was lowered into a silicone oil bath where the temperature israised at 2° C. per minute until it deflects 0.25 mm (0.32 mm for ISOTest No. 75-2).

Notched Charpy Impact Strength: Notched Charpy properties are testedaccording to ISO Test No. ISO 179-1) (technically equivalent to ASTMD256, Method B). This test is run using a Type A notch (0.25 mm baseradius) and Type 1 specimen size (length of 80 mm, width of 10 mm, andthickness of 4 mm). Specimens are cut from the center of a multi-purposebar using a single tooth milling machine. The testing temperature is 23°C., −30° F., or −40° F. as reported below.

Unnotched Charpy Impact Strength: Unnotched Charpy properties are testedaccording to ISO Test No. 180 (technically equivalent to ASTM D256). Thetest is run using a Type 1 specimen (length of 80 mm, width of 10 mm andthickness of 4 mm). Specimens are cut from the center of a multi-purposebare using a single tooth milling machine. The testing temperature is23° C.

Izod Notched Impact Strength: Notched Izod properties are testedaccording to ISO Test No. 180 (technically equivalent to ASTM D256,Method A). This test is run using a Type A notch. Specimens are cut fromthe center of a multi-purpose bar using a single tooth milling machine.The testing temperature is 23° C.

Density and Specific Gravity: Density was determined according to ISOTest No. 1183 (technically equivalent to ASTM D792). The specimen wasweighed in air then weighed when immersed in distilled water at 23° C.using a sinker and wire to hold the specimen completely submerged asrequired.

Vicat softening temperature: Vicat Softening temperature was determinedaccording to method A, with a load of 10 N and according to method Bwith a load of 50 N as described in ISO Test No. 306 (technicallyequivalent to ASTM D1525), both of which utilized a heating rate of 50K/h.

Water absorption was determined according to ISO Test No. 62. The testspecimens are immersed in distilled water at 23° C. until the waterabsorption essentially ceases (23° C./sat).

Complex viscosity: Complex viscosity is determined by a Low shear sweep(ARES) utilizing an ARES-G2 (TA Instruments) testing machine equippedwith 25 mm SS parallel plates and using TRIOS software. A dynamic strainsweep was performed on a pellet sample prior to the frequency sweep, inorder to find LVE regime and optimized testing condition. The strainsweep was done from 0.1% to 100%, at a frequency 6.28 rad/s. The dynamicfrequency sweep for each sample was obtained from 500 to 0.1 rad/s, withstrain amplitude of 3%. The gap distance was kept at 1.5 mm for pelletsamples. The temperature was set at 310° C. for all samples.

Melt strength and melt elongation is performed on ARES-G2 equipped EVFfixture. The flame bar sample was cut as shown in FIG. 7. The same areaof flame bar was used for each run, in order to keep the crystallinityof test sample same and thus to minimize the variation betweenreplicates. A transient strain was applied to each sample at 0.2/s rate.At least triplicate run was done for each sample to obtain arepresentative curve.

Permeation Resistance: The fuel permeation studies were performed onsamples according to SAE Testing Method No. J2665. For all samples,stainless-steel cups were used. Injection molded plaques with a diameterof 3 inches (7.6 centimeters) were utilized as test samples. Thethickness of each sample was measured in 6 different areas. An O-ringViton® fluoroelastomer was used as a lower gasket between cup flange andsample (Purchased from McMaster-Carr, cat# 9464K57, A75). A flat Viton®fluoroelastomer (Purchased from McMaster-Carr, cat# 86075K52, 1/16″thickness, A 75) was die-cut to 3 inch (7.6 cm) OD and 2.5 inch (6.35cm) ID, and used as the upper gasket between the sample and the metalscreen. The fuel, about 200 ml, was poured into the cup, the cupapparatus was assembled, and the lid was finger-tightened. This wasincubated in a 40° C. oven for 1 hour, until the vapor pressureequilibrated and the lid was tightened to a torque 15 in-lb. The fuelloss was monitored gravimetrically, daily for the first 2 weeks followedby twice a week for the rest of the testing period. A blank run was donein the same manner with an aluminum disk (7.6 cm diameter, 1.5 mmthickness) and the result was subtracted from the samples. All sampleswere measured in duplicate. The normalized permeation rate wascalculated following an equilibration period. The permeation rate foreach sample was obtained from the slope of linear regression fitting ofdaily weight loss (gm/day). The normalized permeation rate wascalculated by dividing the permeation rate by the effective permeationarea and multiplying by average thickness of specimen. The averagepermeation rates are reported.

EXAMPLE 1

Materials utilized to form the compositions included the following:

-   -   Polyarylene sulfide: Fortron® 0214 linear polyphenylene sulfide        available from Ticona Engineering Polymers of Florence, Kentucky    -   Impact Modifier: LOTADER® AX8840—a random copolymer of ethylene        and glycidyl methacrylate available from Arkema, Inc.    -   Crosslinking Agent: Terephthalic Acid    -   Disulfide: 2,2-dithiodibenzoic acid    -   Lubricant: Glycolube® P available from Lonza Group Ltd.

Materials were melt mixed using a Coperion co-rotating,fully-intermeshing, twin-screw extruder with an overall L/D of 40 andten temperature control zones including one at the die. A high shearscrew design was used to compound the additives into a resin matrix. Thepolyarylene sulfide, impact modifier and lubricant were fed to the mainfeed throat in the first barrel by means of a gravimetric feeder. Uponmelting and mixing of the above ingredients, the disulfide was fed usinga gravimetric feeder at barrel 6. Materials were further mixed thenextruded through a strand die. The strands were water-quenched in a bathto solidify and granulated in a pelletizer.

Compositions of the samples are provided in Table 1, below. Amounts areprovided as weight percentages based upon the weight of the sample.

TABLE 1 Component Addition Point Sample 1 Sample 2 Lubricant main feed0.3 0.3 Disulfide barrel 6 1.0 Impact Modifier main feed 25.0 25.0Polyarylene Sulfide main feed 74.7 73.7 Total 100.0 100.0

Following formation, samples were tested for a variety of physicalcharacteristics. Results are provided in Table 2, below.

TABLE 2 Sample 1 Sample 2 Melt Viscosity (poise) 3328 4119 TensileModulus (MPa) 1826 1691 Tensile Break Stress (MPa) 43.73 44.98 TensileBreak Strain (%) 96.37 135.12 Std. Dev. 39.07 34.40 Notched CharpyImpact 61.03 53.00 Strength at 23° C. (kJ/m²)

Samples were annealed at 230° C. for 2 hours and re-tested for physicalcharacteristics. Results are provided in Table 3, below.

TABLE 3 Sample 1 Sample 2 Tensile Modulus (MPa) 1994.00 1725.00 TensileBreak Stress (MPa) 45.04 45.20 Tensile Break Strain (%) 58.01 73.76 Std.Dev. 6.60 4.78

As can be seen, Sample 2 exhibited better tensile elongation and lowermodulus before and after annealing. However, no improvement in impactstrength was seen, which is believed to be due to a chain scissionreaction between the disulfide and the polypropylene sulfide.

EXAMPLE 2

Materials as described in Example 1 were melt mixed using a Coperionco-rotating, fully-intermeshing, twin-screw extruder with an overall L/Dof 40 and ten temperature control zones including one at the die. A highshear screw design was used to compound the additives into a resinmatrix. The polyarylene sulfide, impact modifier and lubricant were fedto the main feed throat in the first barrel by means of a gravimetricfeeder. The disulfide was fed using a gravimetric feeder at variouslocations in the extruder; at the main feed throat, at barrel 4 andbarrel 6. The crosslinking agent was fed at barrel 6. Materials werefurther mixed then extruded through a strand die. The strands werewater-quenched in a bath to solidify and granulated in a pelletizer.

Comparative Samples 3 and 4 were formed of the same composition andcompounded by use of a different screw design.

TABLE 4 Addition Point 3 4 5 6 7 8 9 10 Lubricant main feed 0.3 0.3 0.30.3 0.3 0.3 0.3 0.3 Crosslinking barrel 6 — — 0.5 1.0 1.0 0.5 0.5 0.5Agent Disulfide main feed — — — — — 0.30 — — Disulfide barrel 4 — — — —— — 0.3 — Disulfide barrel 6 — — — — — — — 0.3 Impact main feed 15.015.0 15.0 15.0 10.0 15.0 15.0 15.0 Modifier Polyarylene main feed 84.784.7 84.2 83.7 88.7 83.9 83.9 83.9 Sulfide Total 100.0 100.0 100.0 100.0100.0 100.0 100.0 100.0

Following formation, tensile bars were formed and tested for a varietyof physical characteristics. Results are provided in Table 5, below.

TABLE 5 Sample Sample 3 Sample 4 Sample 5 Sample 6 Sample 7 Sample 8Sample 9 10 Melt 2423 — 2659 2749 2067 2349 2310 2763 Viscosity (poise)Density — 1.28 — 1.25 — — — — (g/cm³) Tensile 2076 2800 2177 2207 25511845 2185 2309 Modulus (MPa) Tensile 46.13 — 45.40 48.27 51.71 46.4747.16 47.65 Break Stress (MPa) Tensile 33.68 25 43.97 35.94 26.90 47.5140.85 63.85 Break Strain (%) Elongation 5.17 5 5.59 7.49 4.5 11.78 6.947.00 at Yield (%) Yield 51.07 52 50.76 51.62 59.63 51.07 52.56 51.88Stress (MPa) Notched 22.30 30 23.90 39.40 14.80 12.50 19.70 39.90 CharpyImpact Strength at 23° C. (kJ/m²) Notched 7.8 7 — 10 — — — 10.8 CharpyImpact Strength at −30° C. (kJ/m²) DTUL (° C.) — 100 — 102 — — — — Melt280 280 280 280 280 280 280 280 Temp. (° C.) Water — 0.05 — 0.05 — — — —absorption (%)

Samples were annealed at 230° C. for 2 hours and re-tested for physicalcharacteristics. Results are provided in Table 6, below.

TABLE 6 Sample Sample 3 Sample 4 Sample 5 Sample 6 Sample 7 Sample 8Sample 9 10 Tensile 2383 — 2339 2279 2708 2326 2382 2491 Modulus (MPa)Tensile 52.70 — 53.96 53.11 61.10 56.74 54.81 55.25 Break Stress (MPa)Tensile 29.42 — 20.97 35.76 20.34 31.37 41.23 49.03 Break Strain (%)Std. 6.84 — 6.95 6.66 5.40 2.83 2.65 3.74 Dev.

As can be seen, the highest tensile elongation and highest impactstrength were observed for Sample 10, which includes both thecrosslinking agent and the disulfide added at the same point downstreamduring processing.

FIG. 8 illustrates the relationship of notched Charpy impact strengthover temperature change for Sample 3 and for Sample 6. As can be seen,the thermoplastic composition of Sample 6 exhibits excellentcharacteristics over the entire course of the temperature change, with ahigher rate of increase in impact strength with temperature change ascompared to the comparison material.

FIG. 9 is a scanning electron microscopy image of the polyarylenesulfide used in forming the sample 3 composition (FIG. 9A) and theSample 6 composition (FIG. 9B). As can be seen, there is no clearboundary between the polyarylene sulfide and the impact modifier in thecomposition of FIG. 9B (sample 6).

Tensile bar test specimens of samples 3, 6, and 10 were immersed in 10wt. % sulfuric acid for 500 hours at either 40° C. or 80° C. Tensileproperties and impact properties were measured before and after the acidexposure. Results are summarized in Table 7 below.

TABLE 7 Sample 3 Sample 6 Sample 10 Initial properties Tensile Modulus(MPa) 2076 2207 2309 Tensile Break Stress (MPa) 46.13 48.27 47.65Tensile Break Strain (%) 33.68 35.94 63.85 Charpy notched impact 22.3039.40 39.90 strength at 23° C. (kJ/m²) Properties after 500 hoursexposure in sulfuric acid at 40° C. Tensile Modulus (MPa) 2368 2318 2327Tensile Break Stress (MPa) 48.83 48.48 48.53 Tensile Break Strain (%)10.99 28.28 30.05 Charpy notched impact 18.4 33.6 35.9 strength at 23°C. (kJ/m²) Loss in Charpy notched impact 18 15 15 strength (%)Properties after 500 hour exposure in sulfuric acid at 80° C. TensileModulus (MPa) 2341 2356 2354 Tensile Break Stress (MPa) 49.61 48.0448.86 Tensile Break Strain (%) 10.60 19.88 26.32 Charpy notched impact9.2 31.0 34.0 strength at 23° C. (kJ/m²) Loss in Charpy notched impact59 21 15 strength (%)

The results in the change in Charpy notched impact strength over timeduring exposure to the acid solution at an elevated temperature areillustrated in FIG. 10. As can be seen, the relative loss of strength ofsamples 6 and 10 is much less than the comparison sample.

EXAMPLE 3

Materials as described in Example 1 were melt mixed using a Coperionco-rotating, fully-intermeshing, twin-screw extruder with an overall L/Dof 40 and ten temperature control zones including one at the die. A highshear screw design was used to compound the additives into a resinmatrix. The polyarylene sulfide, impact modifier and lubricant were fedto the feed throat in the first barrel by means of a gravimetric feeder.The crosslinking agent was fed using a gravimetric feeder at the mainfeed throat and at barrel 6. Materials were further mixed then extrudedthrough a strand die. The strands were water-quenched in a bath tosolidify and granulated in a pelletizer.

Compositions of the samples are provided in Table 8, below. Amounts areprovided as weight percentages based upon the weight of the sample.

TABLE 8 Addition Sample Sample Sample Sample Component Point 11 12 13 14Lubricant main 0.3 0.3 0.3 0.3 feed Crosslinking main — 0.5 1.0 — Agentfeed Crosslinking barrel 6 — — — 1.0 Agent Impact main 15.0 15.0 15.015.0 Modifier feed Polyarylene main 84.7 84.2 83.7 83.7 Sulfide feedTotal 100.0 100.0 100.0 100.0

Following formation, tensile bars formed of the samples were tested fora variety of physical characteristics. Results are provided in Table 9,below.

TABLE 9 Sample Sample Sample Sample 11 12 13 14 Melt Viscosity (poise)2649 2479 2258 3778 Tensile Modulus (MPa) 2387 2139 2150 1611 TensileBreak Stress 46.33 49.28 51.81 42.44 (MPa) Tensile Break Strain 24.6222.60 14.45 53.62 (%) Std. Dev. 9.19 1.51 2.23 1.90 Notched Charpy 27.508.50 6.00 39.30 Impact Strength at 23° C. (kJ/m²) Std. Dev. 2.7 1.100.60 2.10

As can be seen, upstream feed of the crosslinking agent decreased theimpact properties of the composition, while downstream feed increasedthe tensile elongation by 118% and room temperature impact strength by43%.

EXAMPLE 4

Materials as described in Example 1 were melt mixed using a Coperionco-rotating, fully-intermeshing, twin-screw extruder with an overall L/Dof 40 and ten temperature control zones including one at the die. A highshear screw design was used to compound the additives into a resinmatrix. The polyarylene sulfide, impact modifier and lubricant were fedto the feed throat in the first barrel by means of a gravimetric feeder.The crosslinking agent was fed using a gravimetric feeder at barrel 6.Materials were further mixed then extruded through a strand die. Thestrands were water-quenched in a bath to solidify and granulated in apelletizer.

Compositions of the samples are provided in Table 10, below. Amounts areprovided as weight percentages based upon the weight of the sample.

TABLE 10 Addition Sample Sample Sample Sample Component Point 15 16 1718 Lubricant main 0.3 0.3 0.3 0.3 feed Crosslinking barrel 6 1.0 1.7 1.01.7 Agent Impact main 25.0 25.0 15.0 15.0 Modifier feed Polyarylene main73.7 73.0 83.7 83.0 Sulfide feed Total 100.0 100.0 100.0 100.0

Following formation, tensile bars formed of the samples were tested fora variety of physical characteristics. Results are provided in Table 11,below.

TABLE 11 Sample Sample Sample Sample 15 16 17 18 Melt Viscosity (poise)4255 4198 2522 2733 Density (g/cm³) 1.2 — — — Tensile Modulus (MPa)1582.00 1572.00 2183.00 2189.00 Tensile Break Stress 45.59 46.29 48.9849.26 (MPa) Tensile Break Strain 125.92 116.40 66.13 48.24 (%) Std. Dev.19.79 9.97 15.36 7.80 Elongation at Yield (%) 23 — — — Yield Stress(MPa) 42 — — — Flex Modulus (MPa) 1946.00 1935.00 2389.00 2408.00Flexural Stress @3.5% 48.30 48.54 68.55 68.12 (MPa) Notched Charpy 55.6051.80 43.60 19.10 Impact Strength at 23° C. (kJ/m²) Std. Dev. 1.00 1.401.50 1.50 Notched Charpy 13 — — — Impact Strength at −30° C. (kJ/m²)Notched Charpy 13.30 12.10 11.26 8.70 Impact Strength at −40° C. (kJ/m²)Std. Dev. 1.50 0.90 0.26 0.50 DTUL (1.8 MPa) (° C.) 97.20 97.60 101.70100.90 Water absorption (%) 0.07 — — —

EXAMPLE 5

Materials as described in Example 1 were utilized except for thepolyarylene sulfide, which was Fortron® 0320 linear polyphenylenesulfide available from Ticona Engineering Polymers of Florence,Kentucky. Materials were melt mixed using a Coperion co-rotating,fully-intermeshing, twin-screw extruder with an overall L/D of 40 andten temperature control zones including one at the die. A high shearscrew design was used to compound the additives into a resin matrix. Thepolyarylene sulfide and impact modifier were fed to the feed throat inthe first barrel by means of a gravimetric feeder. The crosslinkingagent was fed using a gravimetric feeder at barrel 6. Materials werefurther mixed then extruded through a strand die. The strands werewater-quenched in a bath to solidify and granulated in a pelletizer.

Compositions of the samples are provided in Table 12, below. Amounts areprovided as weight percentages based upon the weight of the sample.

TABLE 12 Addition Sample Sample Sample Sample Sample Component Point 1920 21 22 23 Crosslinking barrel 6 — — — 0.1 0.2 Agent Impact main — 1.53.0 1.5 3.0 Modifier feed Polyarylene main 100.0 98.5 97.0 98.4 96.8Sulfide feed Total 100.0 100.0 100.0 100.0 100.0

Following formation, tensile bars formed of the samples were tested fora variety of physical characteristics. Results are provided in Table 13,below.

TABLE 13 Sample Sample Sample Sample Sample 19 20 21 22 23 MeltViscosity (poise) 2435 2684 2942 2287 1986 Tensile Modulus (MPa) 32083207 3104 3245 3179 Tensile Break Stress 67.20 72.94 59.06 63.95 60.80(MPa) Tensile Break Strain 2.46 4.54 11.96 6.31 11.40 (%) Std. Dev. 0.321.11 1.24 2.25 3.53 Flex Modulus (MPa) 3103.00 3173.00 3031.00 3284.003156.00 Flexural Stress @3.5% 105.76 104.74 100.21 109.09 104.81 (MPa)Notched Izod Impact 2.90 5.20 5.60 4.10 4.30 Strength at 23° C. (kJ/m²)Std. Dev. 0.40 0.40 0.40 0.20 0.20 DTUL (1.8 MPa) (° C.) 105.60 104.00103.70 104.20 104.80

EXAMPLE 6

Materials utilized to form the compositions included the following:

-   -   Polyarylene sulfide: Fortron® 0214 linear polyphenylene sulfide        available from Ticona Engineering Polymers of Florence, Kent.    -   Impact Modifier: LOTADER® 4720—a random terpolymer of ethylene,        ethyl acrylate and maleic anhydride available from Arkema, Inc.

-   -   Crosslinking Agent: Hydroquinone    -   Lubricant: Glycolube® P available from Lonza Group Ltd.

Materials were melt mixed using a Coperion co-rotating,fully-intermeshing, twin-screw extruder with an overall L/D of 40 andten temperature control zones including one at the die. A high shearscrew design was used to compound the additives into a resin matrix. Thepolyarylene sulfide, impact modifier and lubricant were fed to the mainfeed throat in the first barrel by means of a gravimetric feeder. Uponmelting and mixing of the above ingredients, the crosslinking agent wasfed using a gravimetric feeder at the main feed for samples 24 and 25and at barrel 6 for samples 26 and 27. Materials were further mixed thenextruded through a strand die. The strands were water-quenched in a bathto solidify and granulated in a pelletizer.

Compositions of the samples are provided in Table 14, below. Amounts areprovided as weight percentages based upon the weight of the sample.

TABLE 14 Addition Sample Sample Sample Sample Sample Component Point 2425 26 27 28 Lubricant main feed 0.3 0.3 0.3 0.3 0.3 Crosslinking barrel6 — — — 0.1 0.2 Agent Crosslinking main feed — 0.1 0.2 — — Agent Impactmain feed 15.0 15.0 15.0 15.0 15.0 Modifier Polyarylene main feed 84.784.6 84.5 84.6 84.5 Sulfide Total 100.0 100.0 100.0 100.0 100.0

Following formation, samples were tested for a variety of physicalcharacteristics. Results are provided in Table 15, below.

TABLE 15 Sample Sample Sample Sample Sample 24 25 26 27 28 MeltViscosity 2435 2797 3251 2847 2918 (poise) Tensile Modulus 2222 21642163 2184 2145 (MPa) Tensile Break 52.03 45.17 46.53 45.47 46.39 Stress(MPa) Tensile Break 36.65 50.91 63.39 38.93 41.64 Strain (%) Std. Dev.9.09 14.9 11.88 7.62 10.42 Elongation at Yield 5.75 5.49 5.76 5.53 5.70(%) Yield Stress (MPa) 52.03 50.21 50.77 51.39 50.85 Flexural Modulus2358.00 2287.00 2286.00 2305.00 2281.00 (MPa) Flexural Stress 70.5168.25 68.03 69.23 68.23 @3.5% (MPa) Notched Charpy 29.80 44.60 50.6042.30 45.90 Impact Strength at 23° C. (kJ/m²) Std. Dev. 4.10 2.40 1.901.90 1.60 Notched Charpy 5.90 9.30 11.00 9.60 9.80 Impact Strength at−40° C. (kJ/m²) Std. Dev. 1.00 0.90 1.20 0.80 1.30 DTUL (1.8 MPa) 99.1093.90 98.20 100.10 99.00 (° C.)

EXAMPLE 7

Materials utilized to form the compositions included the following:

-   -   Polyarylene sulfide:        -   PPS1—Fortron® 0203 linear polyphenylene sulfide available            from Ticona Engineering Polymers of Florence, Kentucky        -   PPS2—Fortron®0205 linear polyphenylene sulfide available            from Ticona Engineering Polymers of Florence, Kentucky        -   PPS3—Fortron®0320 linear polyphenylene sulfide available            from Ticona Engineering Polymers of Florence, Kentucky    -   Impact Modifier: LOTADER® AX8840—a random copolymer of ethylene        and glycidyl methacrylate available from Arkema, Inc.    -   Crosslinking Agent: Terephthalic Acid    -   Lubricant: Glycolube® P available from Lonza Group Ltd.

Materials were melt mixed using a Coperion co-rotating,fully-intermeshing, twin-screw extruder with an overall L/D of 40 andten temperature control zones including one at the die. A high shearscrew design was used to compound the additives into a resin matrix. Thepolyarylene sulfide, impact modifier and lubricant were fed to the mainfeed throat in the first barrel by means of a gravimetric feeder. Uponmelting and mixing of the above ingredients, the crosslinking agent wasfed using a gravimetric feeder at barrel 6. Materials were further mixedthen extruded through a strand die. The strands were water-quenched in abath to solidify and granulated in a pelletizer.

Compositions of the samples are provided in Table 16, below. Amounts areprovided as weight percentages based upon the weight of the sample.

TABLE 16 Addition Sample Sample Sample Sample Sample Sample ComponentPoint 29 30 31 32 33 34 Lubricant main 0.3 0.3 0.3 0.3 0.3 0.3 feedCrosslinking barrel 6 1.0 1.0 1.0 Agent Impact main 15.0 15.0 15.0 15.015.0 15.0 Modifier feed PPS1 main 84.7 83.7 feed PPS2 main 84.7 83.7feed PPS3 main 84.7 83.7 feed Total 100.0 100.0 100.0 100.0 100.0 100.0

Following formation, samples were tested for a variety of physicalcharacteristics. Results are provided in Table 17, below.

TABLE 17 Sample Sample Sample Sample Sample Sample 29 30 31 32 33 34Tensile 2292 2374 2250 2427 2130 2285 Modulus (MPa) Tensile Break 50.9250.18 49.18 53.22 48.01 48.08 Stress (MPa) Tensile Break 5.79 2.84 23.7934.73 23.55 45.42 Strain (%) Std. Dev. 0.99 0.18 11.96 4.01 18.57 18.94Flexural 2279.00 2382.00 2257.00 2328.00 2292.00 2294.00 Modulus (MPa)Flexural Stress 71.11 74.94 69.72 72.39 67.95 68.95 @3.5% (MPa) Notched5.70 3.70 9.10 12.80 19.40 45.40 Charpy Impact Strength at 23° C.(kJ/m²) Std. Dev. 0.90 0.70 0.80 1.00 2.70 7.70 Notched 3.00 2.50 5.105.00 5.10 8.00 Charpy Impact Strength at −40° C. (kJ/m²) Std. Dev. 0.700.30 0.60 0.30 0.40 1.00 DTUL 101.00 105.50 100.00 102.90 99.90 100.40(1.8 MPa) (° C.)

EXAMPLE 8

Materials utilized to form the compositions included the following:

-   -   Polyarylene sulfide: Fortron® 0214 linear polyphenylene sulfide        available from Ticona Engineering Polymers of Florence, Kentucky    -   Impact Modifier: LOTADER® AX8840—a random copolymer of ethylene        and glycidyl methacrylate available from Arkema, Inc.    -   Crosslinking Agent: Terephthalic Acid    -   Lubricant: Glycolube® P available from Lonza Group Ltd.

Materials were melt mixed using a Coperion co-rotating,fully-intermeshing, twin-screw extruder with an overall L/D of 40 andten temperature control zones including one at the die. A high shearscrew design was used to compound the additives into a resin matrix. Thepolyarylene sulfide, impact modifier and lubricant were fed to the mainfeed throat in the first barrel by means of a gravimetric feeder. Uponmelting and mixing of the above ingredients, the crosslinking agent wasfed using a gravimetric feeder at barrel 6. Materials were further mixedthen extruded through a strand die. The strands were water-quenched in abath to solidify and granulated in a pelletizer.

Compositions of the samples are provided in Table 18, below. Amounts areprovided as weight percentages based upon the weight of the sample.

TABLE 18 Addition Sample Sample Sample Sample Sample Sample ComponentPoint 35 36 37 38 39 40 Lubricant main 0.3 0.3 0.3 0.3 0.3 0.3 feedCrosslinking barrel 6 0.75 1.25 1.75 Agent Impact main 15.0 15.0 25.025.0 35.0 35.0 Modifier feed Polyarylene main 84.7 83.95 74.70 73.4564.70 62.95 Sulfide feed Total 100.0 100.0 100.0 100.0 100.0 100.0

Following formation, samples were tested for a variety of physicalcharacteristics. Results are provided in Table 19, below. Sample 39 wasnot injection moldable.

TABLE 19 Sample Sample Sample Sample Sample Sample 35 36 37 38 39 40Melt Viscosity 2323 2452 2955 3821 2025 5462 (poise) Tensile 2281 22982051 1721 — 1045 Modulus (MPa) Tensile Break 47.09 49.09 47.29 46.18 —39.81 Stress (MPa) Tensile Break 28.92 36.42 97.33 110.36 — 96.76 Strain(%) Std. Dev. 6.35 3.13 53.94 8.40 — 1.77 Elongation at 5.28 8.58 36.00108.19 — 95.77 Yield (%) Yield Stress 52.42 53.92 46.50 46.76 — 40.43(MPa) Flexural 2388.00 2349.00 2210.00 1750.00 — 1209.00 Modulus (MPa)Flexural Stress 71.52 71.70 63.15 50.52 — 34.41 @3.5% (MPa) Notched35.15 38.40 57.00 52.70 — 52.10 Charpy Impact Strength at 23° C. (kJ/m²)Std. Dev. 6.22 1.50 1.40 3.40 — 2.10 Notched 8.20 10.70 8.70 18.10 —14.10 Charpy Impact Strength at −30° C. (kJ/m²) Std. Dev. 1.50 1.60 0.200.90 — 0.80 Notched 7.26 9.20 8.00 16.80 — 12.47 Charpy Impact Strengthat −40° C. (kJ/m²) Std. Dev. 1.54 2.30 0.60 0.40 — 0.92 DTUL 99.90103.60 98.10 99.30 — 92.70 (1.8 MPa) (° C.) Water — — — — — 0.1absorption (%)

EXAMPLE 9

Materials utilized to form the compositions included the following:

-   -   Polyarylene sulfide: Fortron® 0214 linear polyphenylene sulfide        available from Ticona Engineering Polymers of Florence, Kentucky    -   Impact Modifier: LOTADER® AX8840—a random copolymer of ethylene        and glycidyl methacrylate available from Arkema, Inc.    -   Crosslinking Agent: Terephthalic Acid    -   Lubricant: Glycolube® P available from Lonza Group Ltd.

Materials were melt mixed using a Coperion co-rotating,fully-intermeshing, twin-screw extruder with an overall L/D of 40 andten temperature control zones including one at the die. A high shearscrew design was used to compound the additives into a resin matrix. Thepolyarylene sulfide, impact modifier and lubricant were fed to the mainfeed throat in the first barrel by means of a gravimetric feeder. Uponmelting and mixing of the above ingredients, the crosslinking agent wasfed using a gravimetric feeder at barrel 6. Materials were further mixedthen extruded through a strand die. The strands were water-quenched in abath to solidify and granulated in a pelletizer.

Compositions of the samples are provided in Table 20, below. Amounts areprovided as weight percentages based upon the weight of the sample.

TABLE 20 Addition Sample Sample Sample Sample Component Point 41 42 4344 Lubricant main 0.3 0.3 0.3 0.3 feed Crosslinking barrel 6 1.0 1.11.25 1.25 Agent Impact main 15 20 25 30 Modifier feed Polyarylene main83.7 78.6 73.45 68.45 Sulfide feed Total 100.0 100.0 100.0 100.0

Following formation, samples were tested for a variety of physicalcharacteristics. Results are provided in Table 21, below.

TABLE 21 Sample Sample Sample Sample 41 42 43 44 Specific Gravity 1.251.20 1.15 1.20 (g/cm³) Tensile Modulus 2200 1600 1200 1700 (MPa) (50mm/min) Tensile Break 50 42 40 46 Strength (MPa) (50 mm/min) Elongationat 40 100 90 75 Break (%) (50 mm/min) Yield Stress (MPa) 55 42 40 48 (50mm/min) Yield Strain (%) 9 25 90 15 (50 mm/min) Flexural Modulus 22001700 1300 1900 (MPa) Flexural Strength 68 50 40 56 @3.5% (MPa) NotchedCharpy 40 55 50 50 Impact Strength at 23° C. (kJ/m²) Notched Charpy 1024 20 20 Impact Strength at −30° C. Unnotched Charpy Not Not Not NotImpact Strength at broken broken broken broken 23° C. DTUL (1.8 MPa) 102100 95 100 (° C.) Water absorption 0.05 0.07 0.1 0.05 (%) Vicatsoftening 270 270 270 270 temp. (A10N, ° C.) Vicat softening 200 160 110180 temp. (B50N, ° C.) Complex viscosity 79.994 289.27 455.19 — (0.1rad/sec, 310° C.) (kPa/sec)

Samples 41, 42, and 43 were tested to determine complex viscosity aswell as melt strength and melt elongation as a function of Henckystrain. As a comparative material, Sample 3 as described in Example 2was utilized. Samples 41, 42 and 43 were done at 310° C. and sample 3was done at 290° C. Results are shown in FIG. 11, FIG. 12, and FIG. 13.

EXAMPLE 10

Sample 42 described in Example 9 was utilized to form a blow molded 1.6gallon tank. The formed tank is illustrated in FIG. 14. Cross sectionalviews of the tank are presented in FIG. 15A and FIG. 15B. The formedtank has a good outer surface with regard to both visual inspection andfeel. As shown in FIG. 15A, an even wall thickness (about 3 mm) wasobtained and minimal sag was observed. As shown in FIG. 15B, thepinch-offs formed an excellent geometry.

EXAMPLE 11

Samples 41, 42, and 43 described in Example 9 were tested to determinepermeation of various fuels including CE10 (10 wt. % ethanol, 45 wt. %toluene, 45 wt. % iso-octane), CM15A (15 wt. % methanol and 85 wt. %oxygenated fuel), and methanol. Sample No. 4 described in Example 2 wasutilized as a comparison material. Two samples of each material weretested.

Table 22, below provides the average sample thickness and effective areafor the samples tested with each fuel.

TABLE 22 Average Sample Sample Thickness (mm) Effective area (m²) CE10Aluminum blank-1 1.50 0.00418 Aluminum blank-2 1.50 0.00418 Sample No.4-1 1.47 0.00418 Sample No. 4-2 1.45 0.00418 Sample No. 41-1 1.470.00418 Sample No. 41-2 1.49 0.00418 Sample No. 42-1 1.47 0.00418 SampleNo. 42-2 1.46 0.00418 Sample No. 43-1 1.45 0.00418 Sample No. 43-2 1.470.00418 CM15A Aluminum blank-1 1.50 0.00418 Aluminum blank-2 1.500.00418 Sample No. 4-1 1.48 0.00418 Sample No. 4-2 1.49 0.00418 SampleNo. 41-1 1.49 0.00418 Sample No. 41-2 1.50 0.00418 Sample No. 42-1 1.470.00418 Sample No. 42-2 1.48 0.00418 Sample No. 43-1 1.46 0.00418 SampleNo. 43-2 1.47 0.00418 Methanol Aluminum blank-1 1.50 0.00418 Aluminumblank-2 1.50 0.00418 Sample No. 4-1 1.49 0.00418 Sample No. 4-2 1.490.00418 Sample No. 41-1 1.49 0.00418 Sample No. 41-2 1.51 0.00418 SampleNo. 42-1 1.48 0.00418 Sample No. 42-2 1.47 0.00418 Sample No. 43-1 1.470.00418 Sample No. 43-2 1.48 0.00418

The daily weight losses for each material and each fuel are shown inFIGS. 16-18. Specifically, FIG. 16 shows the daily weight loss for thesamples during the permeation test of CE10, FIG. 17 shows the dailyweight loss for the samples during the permeation test of CM15A, andFIG. 18 shows the daily weight loss for the samples during thepermeation test of methanol.

The average permeation rates for each sample with each fuel are providedin Table 23. Note that Sample No. 43 takes a longer time to arrive atequilibrium, so the linear regression fitting was generated based ondata between days 42 and 65 for this material, while the linear regressfitting was generated for the other materials between days 32 and 65.For methanol, the linear regression fitting was generated based on databetween days 20 and 65, but with Sample No. 604, the methanol linearregression fitting was generated based on data between days 30 and 65.Some samples show negative permeability, which is because the weightloss of the sample was lower than that of the aluminum blank.

TABLE 23 Average Normalized Normalized Per- Average permeationpermeation meation - Permeation - (g-mm/ (g-mm/ 3 mm 3 mm Sample day-m²)day-m²) thickness thickness CE10 Sample No. 4-1 0.06 0.05 ± 0.01 0.020.02 ± 0   Sample No. 4-2 0.05 0.02 Sample No. 41-1 0.07 0.04 ± 0.040.02 0.01 ± 0.01 Sample No. 41-2 0.01 0.00 Sample No. 42-1 0.06 0.06 ±0   0.02 0.02 ± 0   Sample No. 42-2 0.06 0.02 Sample No. 43-1 2020 2.51± 0.43 0.73 0.84 ± 0.14 Sample No. 43-2 2.81 0.94 CM15A Sample No. 4-10.49 0.18 ± 0.44 0.16 0.06 ± 0.15 Sample No. 4-2 −0.13 −0.04 Sample No.41-1 0.50 0.11 ± 0.55 0.17 0.04 ± 0.18 Sample No. 41-2 −0.27 −0.09Sample No. 42-1 −0.13 0.27 ± 0.58 −0.04 0.09 ± 0.19 Sample No. 42-2 0.680.23 Sample No. 43-1 2.04 2.29 ± 0.35 0.68 0.76 ± 0.12 Sample No. 43-22.53 0.84 Methanol Sample No. 4-1 0.37 0.25 ± 0.18 0.12 0.08 ± 0.06Sample No. 4-2 0.13 0.04 Sample No. 41-1 0.02 0.05 ± 0.05 0.01 0.02 ±0.02 Sample No. 41-2 0.08 0.03 Sample No. 42-1 0.28 0.25 ± 0.05 0.090.08 ± 0.02 Sample No. 42-2 0.21 0.07 Sample No. 43-1 0.27 0.41 ± 0.2 0.09 0.14 ± 0.07 Sample No. 43-2 0.55 0.18 The error was derived fromthe standard deviation of duplicates in each sample.

These and other modifications and variations to the present disclosuremay be practiced by those of ordinary skill in the art, withoutdeparting from the spirit and scope of the present disclosure. Inaddition, it should be understood the aspects of the various embodimentsmay be interchanged, either in whole or in part. Furthermore, those ofordinary skill in the art will appreciate that the foregoing descriptionis by way of example only, and is not intended to limit the disclosure.

What is claimed is:
 1. A fuel line comprising a thermoplasticcomposition, the thermoplastic composition including a polyarylenesulfide and a crosslinked impact modifier, the fuel line being a tubularmember and including a hollow passage therethrough in the axialdirection of the tubular member for passage of a fluid.
 2. The fuel lineof claim 1, wherein the thermoplastic composition has one or more of thefollowing characteristics: a notched Charpy impact strength of greaterthan about 3 kJ/m² as determined according to ISO Test No. 197-1 at 23°C.; a tensile modulus of less than about 3000 MPa as determinedaccording to ISO Test No. 527 at a temperature of 23° C. and a testspeed of 5 mm/min; an elongation at yield of greater than about 4.5% asdetermined according to ISO Test No. 527 at a temperature of 23° C. anda test speed of 5 mm/min; a notched Charpy impact strength of greaterthan about 8 kJ/m² as measured according to ISO Test No. 179-1 at atemperature of −30° C.; a flexural modulus of less than about 2500 MPaas measured according to ISO Test No. 178 at a temperature of 23° C. anda test speed of 2 mm/min; a deflection temperature under load of greaterthan about 80° C. as determined according to ISO Test No. 78 at 1.8 MPa;a halogen content of less than about 1000 ppm; meets the V-0flammability standard at a thickness of 0.2 millimeters; exhibits apermeation resistance of less than about 3 g-mm/m²-day as determinedaccording to SAE Testing Method No. J2665.
 3. The fuel line of claim 1,wherein the fuel line is a single layer fuel tube or a multi-layer fuelhose.
 4. The fuel line of claim 4, wherein the inner layer of themulti-layer fuel hose comprises the thermoplastic composition.
 5. Thefuel line of claim 3, wherein the multi-layer fuel hose comprises aninner layer, at least one intermediate layer, and an outer layer andwherein the at least one intermediate layer and/or the outer layercomprises the thermoplastic composition.
 6. The fuel line of claim 1,wherein the polyarylene sulfide is polypropylene sulfide.
 7. The fuelline of claim 1, wherein the polyarylene sulfide is a functionalizedpolyarylene sulfide.
 8. The fuel line of claim 1, the thermoplasticcomposition further comprising one or more additives.
 9. The fuel lineof claim 1, wherein the crosslinked impact modifier comprises thereaction product of an epoxy functionality of the impact modifier and acrosslinking agent or comprises the reaction product of maleic anhydridefunctionality of the impact modifier and a crosslinking agent.
 10. Thefuel line of claim 1, wherein a first section of the fuel line comprisesthe thermoplastic composition, the first section being adjacent to asecond section of the fuel line that does not comprise the thermoplasticcomposition.
 11. The fuel line of claim 1, wherein the thermoplasticcomposition is free of plasticizers.
 12. A method for forming a fuelline comprising molding a thermoplastic composition to form at least onelayer of the fuel line, the thermoplastic composition comprising apolyarylene sulfide and a crosslinked impact modifier.
 13. The method ofclaim 12, further comprising forming the thermoplastic compositionaccording to a method that includes: feeding the polyarylene sulfide toa melt processing unit; feeding the impact modifier to the meltprocessing unit, the polyarylene sulfide and the impact modifier mixingin the melt processing unit such that the impact modifier becomesdistributed throughout the polyarylene sulfide, the impact modifiercomprising a reactive functionality; and feeding the crosslinking agentto the melt processing unit, the crosslinking agent being fed to themelt processing unit following distribution of the impact modifierthroughout the polyarylene sulfide, the crosslinking agent comprisingreactive functionality that is reactive to the reactive functionality ofthe impact modifier.
 14. The method according to claim 13, wherein themelt processing unit has a length L and a blending length L_(B), andwherein the ratio of L/L_(B) is from about 40 to about 1.1.
 15. Themethod according to claim 13, further comprising feeding a disulfidecompound to the melt processing unit, the disulfide compound comprisingreactive functionality at terminal end(s) of the disulfide compound. 16.The method according to claim 15, wherein the reactive functionality ofthe disulfide compound is the same as the reactive functionality of thecrosslinking agent.
 17. The method according to claim 16, wherein thedisulfide compound and the crosslinking agent are added in conjunctionwith one another.
 18. The method according to claim 13, wherein thecrosslinking agent is a disulfide-free crosslinking agent.
 19. Themethod according to claim 12, wherein the impact modifier comprises anepoxy reactive functionality.
 20. The method according to claim 12,wherein the thermoplastic composition is molded according to anextrusion process comprising one or more of the followingcharacteristics: a compression ratio of between about 2.5:1 and about4:1; utilization of a barrel having a length and a diameter, the ratioof the barrel length to the barrel diameter being from about 16 to about24; utilization of a die, the temperature of the die being from about293° C. to about 310° C.; a head pressure that is from about 690 kPa toabout 6900 kPa.
 21. The method according to claim 20, where theextrusion process utilizes an extruder having at least four zones, thetemperature of the first zone being from about 276° C. to about 288° C.,the temperature of the second zone being from about 282° C. to about299° C., the temperature of the third zone being from about 282° C. toabout 299° C., and the temperature of the fourth zone being from about540° C. to about 580° C.
 22. The method according to claim 12, whereinthe thermoplastic composition is molded according to a co-extrusionprocess.
 23. The method according to claim 22, wherein the thermoplasticcomposition is molded with a second different composition, thethermoplastic composition forming a first layer of the fuel line and thesecond different composition forming a second layer of the fuel line.24. The method according to claim 12, wherein the thermoplasticcomposition is molded according to a blow molding process.